/ˈreɪdɪʌɪ/, U.S. /ˈreɪdiaɪ/, (rare) radiuses.radiusn.
/ˈreɪdɪəs/, U.S. /ˈreɪdiəs//ˈreɪdɪʌɪ/, U.S. /ˈreɪdiaɪ/, (rare) radiuses. I. A rod, bar, or other straight object.† 2. Chiefly Astronomy and Nautical. An instrument formerly used for taking the altitude of the sun or a star; = cross-staff n. 2a, Jacob's staff n. 2a. Also: the upright of a cross (rare). Obsolete.
1. † b. Zoology and Palaeontology (a) The bony spine or sting near the base of the tail of a stingray; (b) the alveolus of a belemnite; (c) the dorsal fin of a fish (cf. sense 3f). Obsolete. rare.
a. Anatomy and Zoology. The slightly shorter of the two bones of the forearm in humans (on the same side as the thumb), which articulates with the humerus and the carpus; the corresponding bone of the forelimb in other tetrapods. Also: one of the bones of the pectoral fin of certain fishes (now restricted chiefly to osteolepiform fossils).
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the world > life > the body > structural parts > bone or bones > bones of arm or leg > bones of arm > [noun] > bones of forearm > radius
speel-bone1307
cubit1398
wand-bone1488
radius1578
wand1634
shuttle1662
spoke-bonea1836
radius bone1910
the world > animals > fish > parts of fish > [noun] > bones (various types of)
grate1481
pharyngeal1791
suboperculum1818
supratemporal1834
shackle-joint1837
mastoid1840
wrist1840
mastoid bone1841
subopercular1841
mesotympanic1846
suprascapula1846
hypobranchials1848
hypotympanic1848
urohyal1848
radius1854
epicentral1866
pterotic1866
mesocoracoid1868
supraclavicle1868
precoracoid1869
symplectic1870
hypural1871
mesopterygoid1871
post-temporal1871
postclavicle1872
brachial1873
urostyle1875
hypercoracoid1876
admaxillary1885
intercalarium1887
palatopterygoquadrate1888
subtectal1888
Weberian apparatus1889
Weberian ossicles1889
radial1890
supracleithrum1903
the world > animals > birds > parts of or bird defined by > [noun] > wing or wings > specific bone in
ulna1831
radius1896
1565 J. Hall Anat. 2nd Pt. ii. 62 in tr. Lanfranc Most Excellent Woorke Chirurg. Then nexte after the elbowe, are the .ii. focilles aforsayde: The vpper most wherof is called in Greke Cercis, in Latin Radius and Focile minus.]
1578 J. Banister Hist. Man i. f. 28 The inferiour part of Radius..is not onely at the end flatted, but also ample, large.
1615 H. Crooke Μικροκοσμογραϕια 782 The whole hand being sustained almost alone by the Radius, hath one and the same motion.
1634 T. Johnson tr. A. Paré Chirurg. Wks. vi. xxvi. 217 The cubite is composed of two bones, the one of which we call the Radius, or Wand.
1697 R. Baker Cursus Osteologicus 23 As Enarthrosis, and Arthrodia, serve for all sorts of motion, Ginglimus serves only for Flexion, and Extension; yet in the Radius and Vlna it serves for Pronation and Supination.
1719 J. Quincy Lexicon Physico-medicum (1722) (at cited word) Altho the Ulna and Radius accompany one another, they touch but at their Extremities.
1739 J. Sparrow tr. H. F. Le Dran Observ. Surg. iii. 12 The Radius of the left Arm was..broke.
1797 C. Vial de Sainbel Elem. Vet. Art (ed. 3) 59 The breadth of the fore-arm, being the effect of the bulk of the muscles which encompass the radius, indicates its strength in action.
1827 J. Abernethy Surg. Wks. II. 72 The carpal bones were..driven upwards, some before, and others behind the ends of the radius and ulna.
1854 R. Owen Struct. Skeleton & Teeth in Orr's Circle Sci.: Org. Nature I. 176 In the salmon..The radius, after expanding to unite with the humerus, the ulna, and the radial carpals, sends a long and broad process downwards and inwards.
1896 A. Newton et al. Dict. Birds: Pt. IV 859 In Birds..there are..only two free carpals—one, generally termed the ‘radial’,..articulating with the distal end of both radius and ulna.
a1933 J. A. Thomson Biol. for Everyman (1934) I. xx. 544 Thus in flight the radius does not move on the ulna.
1970 Trans. Royal Soc. Edinb. 68 230 This edge of the fin [of Eusthenopteron] contains the radius.
2001 Oxoniensia 65 192 Pelvic features and bone measurements of the left radius and ulna indicate a male, c. 1.84 m. tall.
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the world > animals > fish > subclass Elasmobranchii > order Hypotremata > [noun] > member of family Dasyatidae (sting-ray) > part of
radius1657
the world > animals > fish > parts of fish > [noun] > fin or parts of fin > dorsal
back-fin?c1225
adipose fin1789
radius1822
subdorsal1856
dead fin1865
1657 J. Rowland tr. J. Johnstone Hist. Wonderful Things of Nature viii. xiv. 255 Some creatures contain their venome in some part onely, as the Spider-fish in its prickles, the Sea-Ray in the radius.
1661 R. Lovell Πανζωορυκτολογια, sive Panzoologicomineralogia 201 Fork-fish... Their Radius only is poysonsome, which being cut off, the rosted may be eaten.
1753 Chambers's Cycl. Suppl. (at cited word) Many of these radii are found remarkably compressed, bent, or distorted, which is an accident accounted peculiar to the fossils formed in animal moulds.
1822 G. Mantell Fossils S. Downs 229 Dorsal fin, or radius, of a fish allied to the Balistes... It consists of thirteen narrow parallel rays.
c. Entomology. A principal vein (or either of two principal veins) in the basic pattern of insect wing venation, in the anterior part of the wing posterior to the costa. Cf. radial sector n. at radial adj. and n. Compounds.Quot. 1826 refers not to the vein now called ‘radius’, but to the costa. The nomenclature of wing veins, and their numbering, is not fully standardized across all the insect orders.
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1826 W. Kirby & W. Spence Introd. Entomol. III. 626 M. Jurine, being of opinion that a striking analogy exists between the wings of insects and those of birds.., has named the nervures in the anterior margin of the wings of the former, radius and cubitus, as corresponding with the bones so-named in the fore-arm of the latter.]
1887 Amer. Naturalist 21 934 Redtenbacher defines five fields in the fully-developed wing of an insect. These are (1) the costal field, with the costa; (2) the radial field, with the radius and its numerous sectors; [etc.].
1895 J. H. Comstock & A. B. Comstock Man. Study Insects iii. 64 The principal veins of the wing..are termed..the radius [etc.]...Two other veins arising near the base of the wing have been developed: one lying between the media and the radius.
1938 A. D. Imms Gen. Textbk. Entomol. (ed. 4) 39 The radius (R) is typically 5-branched: its main stem is convex and divides into two, of which the first branch (R1) passes directly to the wing margin.
1962 Jrnl. Paleontol. 36 1323/1 Radius (R) is usually the heaviest vein in the wing and always convex (along a ridge).
1994 P. J. Gullan & P. S. Cranston Insects ii. 44/2 All winged insects are believed to share the same groundplan of wing venation consisting of eight veins, named from the anterior to the posterior of the wing as: precosta (PC), costa (C), subcosta (Sc), radius (R), media (M), cubitus (Cu), anal (A) and jugal (J).
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the world > space > relative position > vertical position > [noun] > vertical object or part > main upright part > of a cross
radius1597
shaft1781
the world > the universe > cosmology > science of observation > astronomical instruments > measuring altitude > [noun] > cross-staff
Jacob's staff1559
cross-staff1594
fore-staff1669
radius1745
jackstaff1886
1592 J. Dee in Chetham Misc., Tracts I. 28 There was also an excellent radius astronomicus of ten foote longe, having the staff and cross very curiously divided into parts equal.]
1597 T. Morley Plaine & Easie Introd. Musicke 174 The Transverserie or armes of the crosse contain a canon in the twelfth... The Radius or staffe of the crosse containeth like wise two partes in one.
1674 R. Hooke Animadversions Machina Cœlestis 19 Those Instruments which he chiefly laboured to perfect, he professes to be Quadrants, Sectants, and Octants..rejecting all other Instruments..whether Radii, Astrolabs, Zodiacal or Æquinoctial Rings [etc.]..as more troublesome, and less accurate.
1686 R. Blome Gentlemans Recreation 144 The Sea-men observe it [sc. latitude] by the Sun in the Day, and by the Stars in the Night. They use three Instruments, viz. the Astrolabe, the Radius, and the Triangle.
1745 E. Young Consolation 34 With my Radius (the rich Gift Of Thought nocturnal!) I'll point out to thee Its various Lessons.
1890 J. L. E. Dreyer Tycho Brahe ii. 19 In the following year..[Brahe] provided himself with a ‘radius’, or ‘cross-staff’ as it used to be called in English, one of the few instruments employed by the intrepid navigators who discovered new worlds beyond the ocean.
3. † a. A ray or beam of light or radiant heat. Obsolete.† f. Zoology. In fishes: a fin ray. Obsolete.† g. Entomology. Each of the narrow sections into which the wings of most plume moths are divided. Obsolete. rare.
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the world > matter > light > [noun] > ray or beam
beamc885
rowc1225
stringc1275
steamc1300
light beama1398
shafta1400
rayc1400
strakec1400
rade?a1563
gleed1566
radiation1570
shine1581
rayon1591
stralla1618
radius1620
rule1637
irradiation1643
track1693
emanation1700
spoke1849
spearc1850
slant1856
sword1866
secondary1921
1620 J. Mason Briefe Disc. New-found-land 8 Although their Summer bee some what hotter in regard of the nearenes of the Sunne,..the Radius therof then striking neare at a right Angle, causing a strange reflection, yet would it be much hotter.
1656 J. Sparrow tr. J. Böhme Aurora vi. 107 Jacob..wrestled with him all night, till the dawning of the Day, or Morning Radius brake forth.
1660 R. Coke Justice Vindicated 10 The nearer the radii are reflected to right angles, the hotter it is: and the more obliquely they are reflected, the colder it is.
b. A line in an arrangement of straight lines diverging from a point, like the radii of a circle.
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the world > relative properties > number > geometry > line > [noun] > set or system of > line in
radius1774
ray1856
median1883
symmedian, or symmedian line1885
1677 R. Plot Nat. Hist. Oxford-shire 84 Irradiating all manner of ways into the form of a Globe, the several Selenites, like so many radii, all pointing to the center.
1710 T. Fuller Pharmacopœia Extemporanea 201 It [sc. the Glyster]..driveth the Radii of the Miasme outward.
1774 T. Pennant Tour Scotl. 1772 358 On a live rock is cut the radii of a dial.
1802 C. James New Mil. Dict. (at cited word) In fortification, the radius is distinguished into exterior, interior, oblique, and right radius... The latter is a perpendicular line drawn from the center of a polygon to the exterior side.
1909 C. S. Myers Text-bk. Exper. Psychol. 86 A series of black bands in the form of radii may be observed on that part of the white surface which first stimulates the eye.
1962 T. Kinsella Coll. Poems (1996) 54 Into his tongue Chains are fastened, radii of bronze.
c. A rod, bar, etc., forming one of a set extending in several directions from one point; a spoke of a wheel; a radiating part or filament, etc.In quot. 1691: each of the branchial lamellae of a fish.
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the world > animals > fish > parts of fish > [noun] > gill(s) or parts of
ginnle?c1475
gill vein1683
arista1691
radius1691
fish-ear1748
operculum1752
flap1803
opercle1808
subopercle1822
preoperculum1828
preopercule1842
preopercular1851
interoperculum1855
preoperclec1857
raker1903
the world > space > relative position > inclination > divergence > [noun] > radiating > radiating part
ray1668
radius1691
radiation1770
1691 J. Ray Wisdom of God 58 These papillæ do well resemble the Aristæ or radii of a Fishes Gills.
1726 N. Bailey Universal Etymol. Eng. Dict. (ed. 3) Radius (in mechan.), a spoke, or felloe of a wheel, because they issue like rays from the centre of it.
1805 R. Southey Madoc ii. x. 281 Equal in number,..The spreading radii of the mystic wheel, Revolve.
1817 Ann. Philos. 9 160 Orthite, so named because it always forms straight radii.
1876 Nature 21 Sept. 465/1 A horizontal wheel of iron..having six radii.
1909 Chatterbox 180/1 The rows would become rings and the columns radii like the spokes of a wheel.
1952 T. H. Savory Spider's Web iv In addition to radii and spirals there are certain accessory structures which most webs possess.
2002 Copeia No. 4. 991/1 Scales cycloid; parallel radii present on posterior field of scale.
d. Zoology. Each of the arms or radial divisions of a starfish or other echinoderm; each of the main axes of symmetry corresponding to these. Also: a similar division or axis in a coelenterate.
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the world > animals > invertebrates > subkingdom Metazoa > grade Diploblastica > phylum Coelenterata > [noun] > member of > parts of > radiating part
radius1698
perradius1880
1698 E. Lhuyd Let. 10 Mar. in J. Ray Three Physico-theol. Disc. (1713) ii. iv. 182 Pieces of Lime-stone Rocks..almost wholly compos'd of those Vertebræ, or broken Pieces of the Radii of Sea-Stars, which are commonly call'd Fairy-Stones.
1743 Philos. Trans. 1742–3 (Royal Soc.) 42 p. xv Many of the Star-fish Kind..which usually consist of five equal Radii or Arms, were found wanting, some one, others two, three, or four, of those Radii; and Nature was reproducing in them the Radii wanting.
1879 Q. Jrnl. Microsc. Sci. 19 204 Positions corresponding to those in which the Crinoids are usually figured, viz. with a radius due south.
1880 Nature 4 Mar. 414/1 The first four radii [of a discomedusan hydrozoan] to appear in the course of the growth..are called the per-radii.
1906 E. W. MacBride in Cambr. Nat. Hist. I. 503 The radii [of an echinoid] must be compared to the ambulacral grooves on the oral surface of the arms of Starfish.
1962 D. Nichols Echinoderms iii. 36 Round the mouth is a..ring of closely abutting plates, four ambulacrals in each radius alternating with two adambulacrals in each interradius.
1987 M. S. Laverack & J. Dando Lect. Notes Invertebr. Zool. (ed. 3) xxxi. 177/1 There is often one arm that leads (dominant radius) more frequently than the others.
e. Botany †(a) The ray or outer whorl of ligulate florets surrounding the disc in the flower of a plant of the family Asteraceae ( Compositae); (also, in a partial umbel) a border of enlarged petals (obsolete); †(b) any of the peduncles supporting the partial umbels of a universal umbel; a ray (obsolete); (c) a medullary ray (rare).Sense 3e(c) is apparently only attested in dictionaries or glossaries.
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the world > plants > part of plant > reproductive part(s) > flower or part containing reproductive organs > inflorescence or collective flower > [noun] > of particular type, shape, or arrangement > umbel or ray
spoke1578
umbel1597
muscary1657
umbella1699
radius1727
ray1727
universal umbel1760
umbellet1793
umbellule1793
sertulum1831
the world > plants > particular plants > plants and herbs > according to family > Compositae (composite plants) > [noun] > composite plant > part of plant
flower1530
pale1578
thrum1578
blade1672
floret1672
semi-floscule1720
radius1727
ray1727
semi-floret1729
egret1785
floscule1785
anthodium1812
periclinium1826
pericline1855
chaff-scale1856
phyllary1857
anthode1865
arrowlet1872
1727 P. Blair Pharmaco-botanologia iv. 151 These here consist of a Radius or Row of Semifloscules or half Flourishes, called by Tournefort the Corona.
1729 J. Martyn 1st Lect. Bot. 19 A Ray, Radius..is several Semiflorets set round a Disk..in form of a radiant Star.
1796 Encycl. Brit. III. 448/1 Radius, the rim or outward part, consisting of irregular florets.
1832 J. Lindley Introd. Bot. 110 The peduncles which support the partial umbels are named radii.
1836 J. C. Loudon Encycl. Plants (rev. ed.) 711 Solidago canadensis... Radius hardly exceeding disk.
1880 A. Gray Struct. Bot. 430/1 Ray (Radius), one of the radiating branches of an umbel.
1900 B. D. Jackson Gloss. Bot. Terms 220/1 Radius, the structures known as medullary rays.
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the world > animals > fish > parts of fish > [noun] > fin or parts of fin
finc1000
spitc1275
ray1668
pinna1688
radius1740
spine1774
interneural1854
fin-ray1863
mesopterygium1871
metapterygium1871
radiale1871
finlet1874
propterygium1876
radial1882
axonost1887
lepidotrichium1904
1740 R. Brookes Art of Angling xiii. 40 The Back Fin next the Tail is without any Radii.
1755 Philos. Trans. (Royal Soc.) 49 447 The fins are eight in number... One consisting of seven radii on the back.
1871 Proc. Amer. Philos. Soc. 1869–70 11 560 The anterior radii of the anal fin are elongate.
1890 Amer. Naturalist 24 413 I have called attention to the systematic significance of the connection of the fin radii with the vertebral column.
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1826 W. Kirby & W. Spence Introd. Entomol. IV. 338 Radius.., a single subdivision of a digitate wing.
1848 S. Maunder Treasury Nat. Hist. Gloss. 803/1 Radius, in entomology, a single subdivision of a digitate wing; i.e. when the wings are cleft to the base into several subdivisions.
h. Zoology. In a sea urchin: each of five arched and forked bars set radially at the base (aboral end) of the Aristotle's lantern. Also called compasses. Now rare.
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the world > animals > invertebrates > subkingdom Metazoa > grade Triploblastica or Coelomata > phylum Echinodermata > [noun] > subphylum Eleutherozoa > class Echinoidea > member of (sea-urchin) > parts of > rod-like piece in mouth
radius1877
1877 T. H. Huxley Man. Anat. Invertebrated Animals 576 The Lantern consists of twenty principal pieces—five teeth, five alveoli, five rotulæ, and five radii.
1912 Proc. Royal Soc. B. 85 106 Lowering of pressure..appeared to be caused by contraction of the so-called compass sheet of muscle connecting the five forked radii.
1940 O. E. Lowenstein Parker & Haswell's Text-bk. Zool. (ed. 6) I. xi. 708 With the inner end of each rotula is movably articulated a more slender bar, the radius, which runs outwards, parallel with, and closely applied to, the rotula, to end in a free, bifurcated extremity.
i. Ornithology. A barbule of a feather (barbule n. 2). Usually in plural. Now rare.
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the world > animals > birds > feather > [noun] > part of
pen1381
quill?a1425
dowlc1535
rib1545
web1575
pilec1600
twill1664
beard1688
pinion1691
vane1713
shaft1748
beardlet1804
medulla1826
barb1835
barbule1835
stem1845
feather-pulp1859
aftershaft1867
barbicel1869
filament1870
vexillum1871
scape1872
rachis1874
harl1877
calamus1878
radius1882
ramus1882
scapus1882
cilia1884
1867 W. S. Dallas tr. C. L. Nitzsch Pterylography i. 4 In every perfect feather..I distinguish..4. The barbules (radii, Strahlen).]
1882 H. Gadow in Proc. Zool. Soc. 411 The series of radii or barbules on either side of the rami or barbs.
1910 W. P. Pycraft Hist. Birds xxvi. 442 The radii or barbules [of the owl] are provided with specially elongated ‘fila’ on the upper surface.
1964 A. L. Thomson New Dict. Birds 273/1 The barbs (rami)..are each provided with barbules (radii).
1975 Q. Rev. Biol. 50 51/2 A closer examination reveals tiny barbules (radii) branching from each side of (the ramus of) the barb.
II. Mathematical, geometric, and related uses.
4. Geometry.
a. A straight line from the centre of a circle to its circumference, all such lines being equal in length; a similar line from the centre of a sphere to its surface. Also: the length of any of these lines, as a property of the figure. Cf. diameter n. 1.The circle may be the notional circle implied by a circular arc.The relationship between the radius r of a circle and its circumference c is given by c = 2πr. The area A of the circle is given by A = πr2.
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the world > relative properties > number > geometry > line > [noun] > other
medial line1570
radius1590
lineature1630
foot line1658
rectification1685
axis1734
slant side1824
radiant1842
transverse1867
median1883
bilinear1923
1590 T. Hood tr. P. de La Ramée Elem. Geom. iv. f. 2v A Radius is the right line drawen from the centre to the perimeter.
1635 J. Wells Sciographia 44 As the Radius Is to the cosine of the angle given.
a1652 S. Foster Elliptical Horologiography (1654) 1 Divide the Radius A C into the Sines of 15, 30, 45, 60, 75.
1672 R. Boyle Ess. Origine & Virtues Gems 67 These rows of Planes reaching euery way, almost like so many radious's of a Sphere from the Centre.
1707–8 G. Berkeley Philos. Comm. (1989) 62 Circles several radius's are not similar figures.
1734 tr. P. L. M. de Maupertuis Diss. Cœlestial Bodies 47 in J. Keill Exam. Burnet's Theory of Earth (ed. 2) Our first Method of finding the Curves, by Radii and Angles.
1831 D. Brewster Treat. Optics iii. 23 Let a small tube..be so made that it may be attached to the board along any radius.
1853 J. F. W. Herschel Pop. Lect. Sci. (1873) i. §53. 41 In a circle 22 miles in radius..every town and village was destroyed.
1879 H. Calderwood Relations Mind & Brain iii. 70 A series of fibres, some of which are arranged as radii, others in a circular manner.
1925 Amer. Math. Monthly 32 99 Thus all the eight points such as S and T lie on the circle with center at M and radius L.
1967 A. J. Toynbee Between Maule & Amazon 61 Taking Buenos Aires as your centre-point, describe the circumference of a circle with a four-hundred-miles-long radius.
1990 Sciences Jan. 4/2 The radius of the Earth is measured either by astronomical means or by painstaking land-based geodesy.
b. A line drawn to a point on a curve from a certain point such as a focus. Cf. radius vector n.
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the world > relative properties > number > geometry > line > [noun] > specific relating to a curve
asymptote1656
radius1657
radial1702
subradius1826
1657 J. Moxon Wright's Certain Errors Navigation Detected & Corrected i. xx. 149 [An angle] the Sine whereof 7,692,137 is to the whole Sine 10,000,000 as the right Line O B 275,678 is to B A the Suns Eccentricitie 358,388 wherof B E, the Radius of the Eccentrick, is 10,000,000.
1729 A. Motte tr. I. Newton Math. Princ. Nat. Philos. II. iii. 235 The common centre of gravity of the Earth and Moon moves in an ellipse about the Sun in the focus thereof, and by a radius drawn to the Sun, describes areas proportional to the times of description.
1833 Abstr. Papers Royal Soc. 1815–30 2 407 The angles of reflexion at which this kind of light is restored to polarized light may be represented by the variable radius of an ellipse.
1848 G. Salmon Treat. Conic Sections x. 153 In the hyperbola, the difference of the focal radii is constant.
1875 B. Williamson Elem. Treat. Integral Calculus (rev. ed.) 261 The area between two focal radii of a parabola and the curve.
1930 Geogr. Jrnl. 76 349 The error for a radius of the ellipse inclined at 45° to the axis is independent of p.
1981 M. A. Parker & F. Pickup Engin. Drawing (ed. 3) ii. 79 To draw the tangent to the ellipse at any point P on the curve, bisect the exterior angle between the focal radii F1P and F2P.
5. figurative. Something imagined as resembling the radius of a circle, as one of a set of links to a central point, as the measure of radial growth from a starting point, or in some similar way.
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the world > relative properties > number > geometry > line > [noun] > over circle or sphere
diameter1387
dimetient?a1560
beam1570
dimetient line1601
radiusa1657
diametral1658
ray1690
geodetic1850
geodesic1856
a1657 G. Daniel Trinarchodia: Henry IV xlv, in Poems (1878) IV. 12 Thus when All Causes are mett, their Radij must Spread.
1856 P. E. Dove Logic Christian Faith vi. §5. 369 Phenomena are the radii of Knowledge.
1860 F. W. Farrar Ess. Origin Lang. (1865) 15 The radii of inference from many other sources all converge to the common centre of a similar hypothesis.
1956 E. B. White in New Yorker 7 Apr. 39/1 The long rein, or tape, by which the woman guided her charge counterclockwise in his dull career formed the radius of their private circle, of which she was the revolving center.
2003 Globe & Mail (Toronto) (Nexis) 3 May d12 As the radius of knowledge expands, the circumference of ignorance increases.
6.
a. A circular area, the extent of which is expressed as a specified distance from its centre in all directions. Formerly also in plural.
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the world > space > shape > curvature > roundness > [noun] > circularity > a circle > a circular space > area measured by length of radius
radius1777
rayon1815
1777 J. Richardson Dict. Pers., Arab., & Eng. I. 353/1 Exclusive of a wall immediately round the city, it [sc. Bokhara] has another comprehending fifteen smaller towns, within a radius of about twelve English miles.
1836 Philos. Trans. (Royal Soc.) 126 601 Within a radius of a few hundred feet we have the curious spectacle of hot mineralized springs, a cold mineralized spring, and a cold spring of pure water.
1853 J. H. Stocqueler Mil. Encycl. 124/2 It [sc. a grenade] bursts into many pieces, scattering death and wounds among all who are within its radii.
1862 M. E. Braddon Lady Audley's Secret I. xiii. 206 I shall first go to Audley Court, and look for George Talboys in a narrow radius.
1905 Daily Chron. 16 Dec. 4/7 Bushmen and bushwomen within a radius of forty or fifty miles ride to these functions.
1926 Travel Nov. 39/2 To the north more than sixty millions of people are to be found within a radius of thirty hours' travel.
1948 ‘H. Green’ Concluding 97 The roads are to be watched within a radius of twenty miles.
2005 J. Dicker United States of Wal-Mart xi. 206 Picket every Wal-Mart in a ten-mile radius of your home.
b. spec. A circular area stretching four miles in all directions from Charing Cross in London, beyond which cab fares are higher. Now historical.
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1853 Times 2 Aug. 3/3 Mr. Frewen objected to the radius of four miles from Charing-cross... He proposed, as an amendment, that the outside boundaries of the metropolitan boroughs should be adopted as the limit beyond which the increased charge should commence.
1877 A. Sewell Black Beauty iii. xxxix. 194 We can't charge more than sixpence a mile after the first, within the four mile radius.
1889 Baedeker's London (ed. 7) 28 Beyond the 4-mile radius from Charing Cross the fare is 1s. for every mile.
1899 W. P. Ridge Outside radius (title) Outside the radius. Stories of a London suburb.
c1903 W. Lewis Lett. (1963) 8 I went to a cabman in the rank, and he asked 5/–; so I left him as a blageur [sic]; but it appears that it is without the 4 mile radius, and it is 1/- a mile.
1948 J. Betjeman Sel. Poems in Coll. Poems (1997) 126 Just in the four-mile radius where hackney carriages run.
Compounds
C1.
a. Objective.† radius-bearing adj. Obsolete
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1893 A. Newton et al. Dict. Birds: Pt. 1 245 In Gallinæ there are from 10 to 12 somewhat stiff radius-bearing rami.
b. † radius-finder n. Obsolete rare an instrument for finding two radii (and thereby the centre) of a circle.
radius arm n. = radius rod n.
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society > travel > means of travel > a conveyance > vehicle > vehicles according to means of motion > vehicle moving on wheels > [noun] > parts of vehicle moving on wheels > axle > attached to axle
radius arm1853
strap skein1891
Panhard rod1957
1853 Sci. Amer. 17 Sept. 19/3 Said sliding bar is made adjustable upon a radius arm hung to the center of the wheel.
1913 J. B. Davidson Agric. Engin. lxi. 390 Some rear-mounted [steam tractor] boilers have the main axle mounted with radius arms, that the boiler may be carried on springs and still permit the gearing to be in proper mesh at all times.
1991 Mod. Railways Apr. 175/1 Longitudinal axle location is by angled radius arms which, with the compliance of the primary suspension, gives a degree of self-steering.
radius bar n. = radius rod n.
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society > occupation and work > equipment > machine > machines which impart power > engine > steam engine > [noun] > parts of > bars
cross-head1827
lever1836
radius bar1839
1839 R. S. Robinson Naut. Steam Engine Explained 75 To these levers are also secured the radius bars, which are rods of wrought-iron, proceeding from the side rods.
1853 J. Glynn Treat. Power Water 140 The radius bar carries a pen, the nib of which is in the line of the radius.
1980 R. D. Bent & J. L. McKinley Aircraft Maintenance & Repair (ed. 4) viii. 224/1 When it is desired to make a bend having a given radius, a radius bar having the correct radius for the bend is secured to the clamping bar.
radius bone n. = sense 1a.
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the world > life > the body > structural parts > bone or bones > bones of arm or leg > bones of arm > [noun] > bones of forearm > radius
speel-bone1307
cubit1398
wand-bone1488
radius1578
wand1634
shuttle1662
spoke-bonea1836
radius bone1910
1910 Biol. Bull. 18 88 This thick edge is somewhat comparable to a radius bone.
1964 G. B. Schaller Year of Gorilla x. 248 The left forearm was severely deformed, caused apparently by a fracture of the radius bone.
2000 D. Bellos et al. tr. G. Ifrah Univ. Hist. Numbers iv. 62 The radius bone of a wolf..was discovered..in sediments which have been dated as approximately 30,000 years old.
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1886 Lockwood's Dict. Mech. Engin. (at cited word) Radius finder, a centre square.
radius rod n. a pivoting rod or arm; spec. (a) a rod pivoted at one end so that the other end can move in a circle or an arc of a circle, used esp. as one of a pair in the parallel motion of a steam engine; (b) (in the suspension of a car or other four-wheeled vehicle) either of a pair of arms attached to the axle and pivoting on the frame, preventing lateral movement of the axle.
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society > occupation and work > equipment > machine > parts of machines > other parts > [noun] > converters
pallet1676
rack1717
parallel motion1728
rack and pinion?c1780
rack bara1824
radius rod1834
rack rod1839
1834 Philos. Trans. (Royal Soc.) 124 324 Two forces.., one at right angles to, and one in the direction of, the radius rod.
1858 R. Murray Marine Engines (ed. 3) Gloss. Radius rods or bars,..are the guiding rods in a parallel motion.
1907 Westm. Gaz. 9 Nov. 14/2 The Daimler Company..have designed their chain-cases to act at the same time as radius-rods.
1946 Happy Landings July 2/1 The inner radius rod of the starboard undercarriage was pulled away from the undercarriage.
1991 Sports Illustr. 30 Sept. 74/2 He was racing on the lead with three or four laps to run and a bolt fell out of the radius rod—part of the car's suspension—and the rod flew right up next to him.
radius saw n. a machine saw consisting of a circular blade suspended from a pivoted horizontal arm; cf. circular saw n. at circular adj. and n. Compounds 1.
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a1884 E. H. Knight Pract. Dict. Mech. Suppl. 735/2 Radius Saw, a machine saw in which the circular saw is journaled on the end of a radial arm, pivoted below to a shaft, on which is placed the driving pulley.
1963 Valley Independent (Monessen, Pa.) 27 Sept. (advt.) De Walt radius saw. Make offer.
2001 Intelligencer (Doylestown, Pa.) 20 Sept. (advt.) Tools: Portable welding machine..radius saw.
C2. Compounds with of.
a. Mathematics, Physics, and in other technical disciplines, as radius of concavity, radius of convexity, radius of dissipation, radius of evolution, radius of explosion, radius of inversion, radius of rupture, etc.radius of curvature: see radius of curvature n. at curvature n. Phrases a.
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1728 E. Chambers Cycl. (at cited word) The Radius of the Evolute..is the Part of the Thread comprized between any Point where it is a Tangent to the Evolute, and the correspondent Point, where it terminates on the new Curve.
1738 R. Smith Compl. Syst. Opticks II. 310 If these measures are the same, set it down as the exact radius of concavity of your speculum.
1741 J. Jurin Let. 22 The pupil contracts to a narrower aperture, and the radius of dissipation..is thereby lessened.
1834 J. S. Macaulay Treat. Field Fortification 189 In common mines the horizontal radius of rupture is equal to 1¾ times the line of least resistance... In a vertical direction, this radius is of the same length as the radius of explosion.
1856 T. Dick Compl. Wks. II. 33/1 Convex mirrors..are frequently employed by painters for reducing the proportions of the objects they wish to represent, as the images of objects diminish in proportion to the smallness of the radius of convexity.
1877 Proc. Amer. Philos. Soc. 1876–7 16 498 Saturn's rotating, relative to its orbital velocity, has been accelerated in the ratio of its initial-rupturing radius to Earth's radius of rupture.
1937 Vidette-Messenger (Valparaiso, Indiana) 3 Dec. 6/8 Their radius of explosion was three meters and therefore [it] was believed they were designed to be used to create panic.
1994 Micropaleontology 40 244/1 Posterior border with small radius of convexity.
2003 What Papers Say (Russia) (Nexis) 24 Dec. The missile did not have to perform additional maneuvers near the target, since it had a big radius of explosion.
b.
radius of action n. [compare French rayon d'action (1826 or earlier in a military context), German Aktionsradius (c1900)] Military the maximum distance that an aircraft, ship, or other vehicle can travel away from its base in a given time and without the need for refuelling.
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society > travel > air or space travel > a means of conveyance through the air > aeroplane > qualities and parameters of aircraft > [noun] > range
radius of action1887
cruising range1922
range1922
turning radius1967
1887 Times 16 Sept. 6/2 The radius of action at 10 knots speed [will be] 8,000 miles.
1908 Aeronaut. Jrnl. Apr. 44/2 In a 10 hours' run a distance of 300 kilm. (186 miles) might be traversed, the radius [of] action being 150 kilm.
1992 D. Wood Jane's World Aircraft Recognition Handbk. (ed. 5) 221 Capable of Mach 2 at altitude, the Rafale will have a low-level combat radius of action of just over 1,000 km.
radius of gyration n. Mathematics and Engineering a distance such that if all the mass of a rotating body were at this distance from the axis of rotation, the moment of inertia of the body would be the same; (equivalently) the square root of the ratio of the moment of inertia of a body to its mass.
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1819 Philos. Trans. (Royal Soc.) 109 94 If we put k for the radius of gyration with respect to the centre of gravity.
1882 G. M. Minchin Uniplanar Kinematics 110 M = mass of the whole body and k its radius of gyration about GH.
1987 E. H. J. Pallett Aircraft Electr. Syst. (ed. 3) ix. 142/1 The motor armature together with a concentrically mounted outer rim forms the gyroscope rotor, the purpose of the rim being to increase the rotor mass and radius of gyration.
radius of torsion n. [after French rayon de torsion (1845 or earlier)] Mathematics the reciprocal of the torsion (torsion n. 1e) of a curve in three dimensions.
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the world > relative properties > number > geometry > curve > [noun] > torsion > reciprocal of
radius of torsion1862
1862 G. Salmon Treat. Analytic Geom. Three Dimensions xi. 270 Following the analogy of the radius of curvature which is ds/dθ, the later French writers denote the quantity ds/dη by the letter r, and call it the radius of torsion.
1945 Amer. Math. Monthly 52 221 R2 = ρ2 + τ2ρ′2, where τ is the radius of torsion of the curve.
1997 Internat. Jrnl. Solids & Structures 34 2499 For a skew line we have to define also the radius of torsion.
This entry has been updated (OED Third Edition, June 2008; most recently modified version published online June 2022).
radiusv.
/ˈreɪdɪəs/, U.S. /ˈreɪdiəs/ transitive. To round off (an edge); to make (a corner or end) curved.
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the world > space > shape > curvature > curve or bend [verb (transitive)] > so as not to be angular
to round off1676
radius1935
1935 Philos. Trans. (Royal Soc.) A. 235 33 It is radiused on each axis, and it is dynamically and statically balanced with extreme care.
1954 Electronic Engin. 26 538/1 All corners and bends should be ‘radiused’, i.e. finished with as large a radius as possible.
1962 Engineering 6 July 10/1 The effect of radiusing the corners is also discussed.
1972 A. Greer & W. H. Howell Mech. Engin. Craft Stud. II. iii. 157 (table) Millsaw. For sharpening circular saws, radiusing slots.
1998 Gramophone Jan. 122/3 All the vertical edges are radiused to the full thickness of the material and then smoothed and lacquered to a good colour match.
This entry has been updated (OED Third Edition, June 2008; most recently modified version published online March 2022).
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n.1578
v.1935