tangentadj.n.
/ˈtandʒənt/ A. adj.
1. † b. Crystallography. Applied to a plane replacing an edge or solid angle of a crystal (also called a secant plane: see secant adj.). Obsolete.
a. Geometry. Of a line or surface in relation to another (curved) line or surface: Touching, i.e. meeting at a point and (ordinarily) not intersecting; in contact. Also as quasi-adv.A surface may also be tangent to another surface along a line (e.g. a plane in contact with a cylinder). In quot. 1869, Taking place along a tangent. Cf. B. 1b.
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the world > relative properties > number > geometry > line > [adjective] > touching another
contingent?a1560
tangent1594
concurrenta1721
tangential1854
the world > relative properties > number > geometry > line > [adverb] > tangentially
tangentially1839
tangentally1891
tangent1936
1594 T. Blundeville Exercises ii. f. 47v Our moderne Geometricians haue of late inuented two other right lines belonging to a Circle called lines Tangent, and lines Secant.
1644 K. Digby Two Treat. i. xiii. 114 The reflexion must follow the nature of tangent surfaces.
1713 G. Berkeley in Guardian 5 Aug. 1/1 Hence..the Earth..without flying off in a Tangent Line, constantly rolls about the Sun.
1866 R. A. Proctor Handbk. Stars 33 The cone, instead of being a tangent-cone, is supposed to be a secant-cone, intersecting the sphere.
1869 J. Tyndall in Fortn. Rev. 1 Feb. 245 All the vibrations tangent to the little circle..are reflected perfectly polarized.
1876 Catal. Special Loan Coll. Sci. Apparatus S. Kensington Mus. §102 Model exhibiting the simultaneous transformation..of the tangent paraboloid of the conoïd into the tangent plane of the cylinder.
1936 A. W. Clapham Romanesque Archit. W. Europe viii. 167 The subsidiary towers..at Mainz and Laach..are set axially and tangent at the ends of the transept.
1977 Sci. Amer. Aug. 37/1 The radiation is emitted tangent to these trajectories.
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the world > matter > chemistry > crystallography (general) > crystal (general) > crystal symmetry > [adjective] > replacement of
truncated1794
tangent1823
1823 H. J. Brooke Familiar Introd. Crystallogr. 109 Edges replaced by tangent planes.
1851 T. Wright & G. F. Richardson Introd. Geol. (new ed.) v. 88 Crystals often present the appearance of having lost their edges and solid angles, which are then said to be replaced by tangent planes.
c. transferred. Said of the wheel of a bicycle or tricycle having the spokes tangent to the hub.
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society > travel > means of travel > a conveyance > vehicle > vehicle propelled by feet > [adjective] > of or relating to cycles > type of wheel
tangent1886
1886 Bicycling News 6 Aug. 664/1 Laced tangent wheels, hollow rims, Hancock's tyres.
2. figurative. ‘Flying off at a tangent’ (see B. 1c); divergent, erratic.
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the world > movement > motion in a certain direction > change of direction of movement > [adjective] > deviating from straight course
wrongc1440
swerving1534
wrya1586
wriedc1595
diverted1608
dissilient1656
deviatory1702
out-of-the-waya1732
tangent1787
wide1827
deflected1860
tangential1867
deviative1878
deviating1883
the world > relative properties > relationship > relevance or pertinence > [adjective] > irrelevant
foreigna1393
unpertinentc1400
impertinentc1450
peregrine1532
far-fet1533
exorbitant1534
unrelevant1558
stravagant1565
fremd1581
unappliable1588
misapplied1596
immaterial1598
far-fetched1607
misdevoted1623
unappertaining1645
irrelativea1657
inapposite1661
unconcerned1683
scandalous1750
uncentral1782
irrelevant1786
tangent1787
inappertinent1814
unappropriate1818
tangential1867
1787 R. Burns Let. 23 Apr. (2001) I. 108 If once this tangent flight of mine were over, and I were returned to my wonted leisurely motion in my old circle.
1799 E. Dubois Piece Family Biogr. I. 152 The voluble loquacity and tangent style of reasoning of their new companion.
3. In general sense.
a. Touching, contiguous.
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the world > space > distance > nearness > [adjective] > contiguous
contiguate?a1475
contiguec1550
attingent1578
contigual1610
contiguous1611
touching1618
attiguous1676
tangent1833
1833 H. Ellis Elgin Marbles I. v. 107 Beaten together till the tangent surfaces were fitted to each other.
b. Of or pertaining to touch; tangent sense, sense of touch.Apparently an isolated use.
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the world > physical sensation > touch and feeling > [adjective]
tactic1625
tactive1634
tactual1642
tactilea1706
tangent1802
haptic1860
1802 E. Darwin Orig. Society iii. 424 Say, did these fine volitions first commence From clear ideas of the tangent sense?
B. n.1878 A. J. Hipkins in Grove Dict. Music I. 367 The tangents..not only produced the tones but served..to measure off the vibrating lengths required for the pitch of the notes.1896 C. W. Naylor Shakspere & Music 68 (note) The German clavichord had ‘tangents’ of brass at the ends of the key levers.
1. Mathematics (elliptical for tangent line.) [= French, German tangente.]
a. Trigonometry. One of the three fundamental trigonometrical functions (cf. secant n. a, sine n.2 2), originally considered as functions of a circular arc, now usually of an angle (viz. that subtended by such arc at its centre): originally. The length of a straight line perpendicular to the radius touching one end of the arc and terminated by the secant drawn from the centre through the other end; in modern use, the ratio of this line to the radius, or (equivalently, as a function of the angle) the ratio of the side of a right-angled triangle opposite the given angle (if acute) to that of the side opposite the other acute angle (the tangent of an obtuse angle being numerically equal to that of its supplement, but of opposite sign). Abbreviated tan.Tables of tangents and cotangents were constructed and used by the Arab mathematicians of the 9th and 10th centuries (see Nallino Al Battani, Opus astronomicum, Milan 1903, i. 182); but began to be constructed in Christendom late in the 15th centuries The names tangens and secans, introduced by Thos. Fincke (Finkius) in 1583, had no connection with the names used by the Arabs.
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the world > relative properties > number > geometry > [noun] > branches of > trigonometry > functions of
right sine1581
sine1593
secant1594
tangent1594
secans1599
cosine1635
cotangent1635
cosecant1706
sec.-
1583 T. Finck Geometriæ Rotundi v. 64 De semicirculi sinibus, tangentibus, secantibus.
1583 T. Finck Geometriæ Rotundi v. 73 Recta sinibus connexa est tangens peripheriæ aut eam secans.]
1594 T. Blundeville Exercises ii. f. 55v Of which Arke the line A.D. is the Tangent, and the line C.D. is the Secant thereof.
1635 J. Wells Sciographia 47 So is the tangent of R. Z. P. To the cotangent of R. P. Z.
1658 E. Phillips New World Eng. Words Tangent,..a Mathematical Term used chiefly in Astronomy,..signifies, a right line perpendicular to the Diameter drawn by the one extream of the given Arch, and terminated by the Secant.
1690 W. Leybourn Cursus mathematicus 397 Which Scales of Tangents..let be extended to 75 deg. at least.
1728 H. Pemberton View Sir I. Newton's Philos. 366 The refracting powers..will be in the duplicate proportion of the tangents of the least angles, which the refracted light can make with the surfaces of the refracting bodies.
1828 O. Gregory Hutton's Course Math. (ed. 9) II. 3 As the arc increases from o, the sines, tangents, and secants, all proceed increasing, till the arc becomes a whole quadrant.., and then the sine is the greatest it can be..; and both the tangent and secant are infinite.
b. Geometry. A straight line which touches a curve (or curved surface), i.e. meets it at a point and being produced does not (ordinarily) intersect it at that point. spec. in Surveying, a tangent to a curve at a point ( tangent point) where the curve starts or finishes; frequently attributive, as tangent distance, tangent length, the length of such a tangent from the tangent point to its intersection with the other tangent.In Higher Geometry a tangent is regarded as the limiting position of a line intersecting a curve when the two (or more) points of intersection coincide, and is hence defined as a straight line passing through two (or more) consecutive points of the curve. If the curve be conceived as traced by a moving particle, the tangent at any point of it represents the direction of motion at that point; hence a body moving in a curve, when the restraining force is withdrawn, flies off at a tangent, i.e. along the tangent (cf. the figurative use in B. 1c). At a point of inflection, where the curvature (i.e. deviation from the straight line) changes its direction, the tangent intersects as well as touches the curve.
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the world > relative properties > number > geometry > line > [noun] > tangent
touchline1551
adscript1636
tangent1655
focal tangent1706
semi-tangent1823
tractor1867
bitangent1873
slope1889
the world > the earth > earth sciences > geography > map-making > surveying > [noun] > point at end of curve
tangent point1850
the world > the earth > earth sciences > geography > map-making > surveying > [noun] > a survey line > tangent at end of curve
tangent1850
the world > the earth > earth sciences > geography > map-making > surveying > [noun] > distances measured between points or lines
easting1652
northing1652
southing1652
westing1652
offset1725
vertical interval1885
horizontal equivalent1889
tangent distance1983
1655 T. Gibson Syntaxis Mathematica xiii. 142 To draw a tangent [cf. 1551 Recorde Pathway, touche line] to any point assigned in any section, or from any point without the section.
1704 J. Harris Lexicon Technicum I Tangent, of a Parabola, (or other Conick Section, or Geometrical Curve) is a Right Line Drawn, cutting the Ax Produced, and touching the Section in one Point without cutting it.
1706 W. Jones Synopsis Palmariorum Matheseos 221 A Tangent to any point of the Circumference [of a circle] is Perpendicular to the Radius drawn to that Point.
1832 Nat. Philos. (Libr. Useful Knowl.) II. Introd. Mechanics p. xvi If a stone, whirled round in a sling, gets loose at the point A.., it flies off in the direction AB: this line is called a tangent.
1850 T. Baker Rudimentary Treat. Land & Engin. Surv. ii. ii. 171 Find the radii, as BO, CO′; the tangent point, as C′; and the junction point, as C, with the position of the common tangent at the junction point.
1862 W. J. M. Rankine Man. Civil Engin. i. v. 111 The places where permanent marks of the course of the line are chiefly required are on the tangents of curves.
1902 R. E. Middleton et al. Treat. Surveying II. v. 61 Find length of tangent for a 3° curve with central angle of 35° 42′.
1978 J. G. McEntyre Land Surv. Syst. x. 329 An easement curve is a transition curve utilized to increase the degree of curvature gradually from the tangent point to the circular portion of a curve.
1983 J. C. McCormack Surveying Fund. xxi. 384 The tangent distances are taped from the P.I. [sc. point of intersection] down both tangents to locate the P.C. and P.T.
c. In general use, chiefly figurative from b, esp. in phrases (off) at, in, upon a tangent, i.e. off or away with sudden divergence, from the course or direction previously followed; abruptly from one course of action, subject, thought, etc., to another.
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the world > movement > motion in a certain direction > change of direction of movement > changing direction of movement [phrase] > aside from course > suddenly
(off) at, in, upon a tangent1771
the world > relative properties > relationship > relevance or pertinence > [phrase] > irrelevant
of purpose (also (out) of (a) (set) purpose)a1382
wide of (also from) the mark1536
neither off nor on1549
from the purpose1561
from (also out of) the bias1600
from the matter1658
(off) at, in, upon a tangent1825
1771 T. Smollett Humphry Clinker II. 143 After having twelve times described this circle, he lately flew off at a tangent to visit some trees at his country-house in England.
1815 tr. V. J. E. de Jouy Paris Chit-chat II. 92 The passengers on the roof, being at the highest point of projection flew off in a tangent, and were precipitated..into a field of new-mown hay.
1825 J. Bentham Rationale Reward 393 That manner which they have..of flying off in tangents when they are pressed.
1865 W. E. H. Lecky Hist. Rationalism (1878) I. 284 (note) Flying off at a tangent from his main subject.
1875 W. D. Whitney Life & Growth Lang. viii. 150 To abandon the established habits of speech and go off upon a tangent.
1879 M. E. Braddon Cloven Foot x Smoking his cigar, and letting his thoughts wander away at a tangent every now and then.
2. The upright pin or wedge fixed at the back of each of the keys of a clavichord, which on the depression of the key pressed up against the string and caused it to sound, acting also as a bridge to determine the pitch of the note. [= German tangent.]
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society > leisure > the arts > music > musical instrument > keyboard instrument > stringed keyboards > [noun] > clavichord > wedge or bridge
tangent1878
1614 M. Praetorius Syntagma Musicum III. 68 Es hat aber ein solch Geigenwerk an statt der Tangenten [etc.].]
3. Short for tangent scale n., tangent galvanometer n. at Compounds.
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society > armed hostility > military equipment > weapon > device for discharging missiles > firearm > parts and fittings of firearms > [noun] > sight > types of
dispart1578
telescopic sight1674
plain sight1686
aim-frontlet1745
hausse1787
foresight1806
gloaming sight1817
night-sight1822
bead1831
leaf1832
backsight1847
globe sight1847
pendulum hausse1850
hindsight1851
tangent scale1859
tangent1861
tangent backsight1862
training pendulum1862
training level1863
peep sight1866
dispart-sight1867
notch sight1867
buck-horn1877
orthoptic1881
aperturea1884
pinball-sighta1884
dispart patch1884
sight bar1884
flap-sight1887
barley-corn1896
ring sight1901
riflescope1902
spotting scope1904
tangent sight1908
Aldis sight1918
wind-sight1923
scope sight1934
gyro-sight1942
the world > matter > physics > electromagnetic radiation > electricity > electric current > [noun] > measurement of galvanic currents > apparatus for > type of
thermo-galvanometer1867
tangent galvanometer1873
ballistic galvanometer1875
tangent1905
string-galvanometer1909
tangent compass-
1861 W. H. Russell in Times 14 May His guns were without screws, scales, or tangents.
1905 W. H. Preece & J. Sivewright Telegraphy 404 Perhaps the most useful galvanometer for general testing purposes is the Tangent.
4. A straight section of railway track. U.S. colloquial.
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1895 I. K. Funk et al. Standard Dict. Eng. Lang. II.
Compounds
Combinations and special collocations. (Some of these are examples of the adjective qualifying a noun) For tangent cone, tangent line, plane, surface, etc., see A. 1; for tangent distance, tangent length, tangent length at sense B. 1b.
tangent backsight n. = tangent scale n. (a).
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society > armed hostility > military equipment > weapon > device for discharging missiles > firearm > parts and fittings of firearms > [noun] > sight > types of
dispart1578
telescopic sight1674
plain sight1686
aim-frontlet1745
hausse1787
foresight1806
gloaming sight1817
night-sight1822
bead1831
leaf1832
backsight1847
globe sight1847
pendulum hausse1850
hindsight1851
tangent scale1859
tangent1861
tangent backsight1862
training pendulum1862
training level1863
peep sight1866
dispart-sight1867
notch sight1867
buck-horn1877
orthoptic1881
aperturea1884
pinball-sighta1884
dispart patch1884
sight bar1884
flap-sight1887
barley-corn1896
ring sight1901
riflescope1902
spotting scope1904
tangent sight1908
Aldis sight1918
wind-sight1923
scope sight1934
gyro-sight1942
1862 Internat. Exhib.: Illustr. Catal. Industr. Dept. II. xi. §2612 The Tangent back-sight is elevated by a rack and pinion, the latter having a micrometer wheel for finer readings than the divisions on the tangent stem allow.
tangent balance n. a balance in which the weight is shown on a graduated arc by a pointer attached to the beam; the bent-lever balance, common as a letter-balance.
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tangent compass n. = tangent galvanometer n.
tangent galvanometer n. a galvanometer in which the tangent of the angle of deflection of the needle is proportional to the strength of the current passing through the coil.
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the world > matter > physics > electromagnetic radiation > electricity > electric current > [noun] > measurement of galvanic currents > apparatus for > type of
thermo-galvanometer1867
tangent galvanometer1873
ballistic galvanometer1875
tangent1905
string-galvanometer1909
tangent compass-
1873 J. C. Maxwell Treat. Electr. & Magn. (1881) II. 325 The current is..proportional to the tangent of the deviation, and the instrument is therefore called a Tangent Galvanometer.
1876 W. H. Preece & J. Sivewright Telegraphy 267 The insulation resistance is the only test which is taken by means of the tangent-galvanometer.
tangent scale n. (a) in Gunnery, a kind of breech-sight in which the heights of the steps or notches correspond to the tangents of the angle of elevation; (b) a graduated scale indicating the tangents of angles (see quot. 1902).
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the world > relative properties > measurement > measuring instrument > [noun] > graduated instruments > graduated scale > other scales
tangent scale1859
mirror scale1889
Modulor1948
society > armed hostility > military equipment > weapon > device for discharging missiles > firearm > parts and fittings of firearms > [noun] > sight > types of
dispart1578
telescopic sight1674
plain sight1686
aim-frontlet1745
hausse1787
foresight1806
gloaming sight1817
night-sight1822
bead1831
leaf1832
backsight1847
globe sight1847
pendulum hausse1850
hindsight1851
tangent scale1859
tangent1861
tangent backsight1862
training pendulum1862
training level1863
peep sight1866
dispart-sight1867
notch sight1867
buck-horn1877
orthoptic1881
aperturea1884
pinball-sighta1884
dispart patch1884
sight bar1884
flap-sight1887
barley-corn1896
ring sight1901
riflescope1902
spotting scope1904
tangent sight1908
Aldis sight1918
wind-sight1923
scope sight1934
gyro-sight1942
1859 F. A. Griffiths Artillerist's Man. (1862) 51 A Tangent scale is affixed to the breech of Guns, and Howitzers, by means of which the requisite elevation may be given.
1902 T. O'C. Sloane Standard Electr. Dict. Tangent scale, an arc of a circle in which the number of graduations in any arc starting from zero are proportional to the tangent of the angle subtended by such arc. The system is for use with tangent galvanometers.
tangent screw n. a screw working tangentially upon a toothed circle or arc so as to give it a slow motion for delicate measurements or adjustments.
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the world > relative properties > measurement > measuring instrument > [noun] > graduated instruments > graduated scale > movable scale or vernier > adjustment screw
tangent screw1862
1862 Internat. Exhib.: Illustr. Catal. Industr. Dept. II. xiii. 5/2 Circumferenter or miner's dial, with tangent screw adjustment.
1877 E. H. Knight Pract. Dict. Mech. Tangent-screw, an endless screw tangentially attached to the index-arm of an instrument of precision, enabling a delicate motion to be given to the arm after it has been clamped to the limb, and permitting angular measurements to be made with greater exactness than could be done were the movement entirely effected by hand.
tangent sight n. = tangent scale n. (a).
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society > armed hostility > military equipment > weapon > device for discharging missiles > firearm > parts and fittings of firearms > [noun] > sight > types of
dispart1578
telescopic sight1674
plain sight1686
aim-frontlet1745
hausse1787
foresight1806
gloaming sight1817
night-sight1822
bead1831
leaf1832
backsight1847
globe sight1847
pendulum hausse1850
hindsight1851
tangent scale1859
tangent1861
tangent backsight1862
training pendulum1862
training level1863
peep sight1866
dispart-sight1867
notch sight1867
buck-horn1877
orthoptic1881
aperturea1884
pinball-sighta1884
dispart patch1884
sight bar1884
flap-sight1887
barley-corn1896
ring sight1901
riflescope1902
spotting scope1904
tangent sight1908
Aldis sight1918
wind-sight1923
scope sight1934
gyro-sight1942
1908 Treat. Serv. Ordn. Royal Artill. 513 The tangent sights consist of triangular nickel-plated steel bars graduated on the rear face.
This entry has not yet been fully updated (first published 1910; most recently modified version published online June 2022).
tangentv.
rare.
intransitive. To go off or away at a tangent (see tangent adj. 1c); to fly off at an angle.
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the world > movement > motion in a certain direction > change of direction of movement > change direction of movement [verb (intransitive)] > diverge from course > specifically of things
wryc1374
awry1604
run1846
tangent1920
1920 F. Niven Tale that is Told vii. 44 They are always tangenting away, not from what I have said, but from what they imagine I have said.
1940 ‘Gun Buster’ Return via Dunkirk ii. i. 85 The empty sardine tin that the Babe pitched, tangented off the side of his tin hat into the long grass.
1974 K. Millett Flying (1975) ii. 201 She chuckles and then tangents off to some article..she read.
This entry has not yet been fully updated (first published 1986; most recently modified version published online June 2019).
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adj.n.1594
v.1920