octahedronn.

Brit.

/ˌɒktəˈhiːdrən/, U.S.

/ˌɑktəˈhidrən/

Inflections: Plural octahedra, octahedrons.

Forms: 1500s 1800s octohedron, 1500s–1700s octaedrum, 1500s–1700s octahedrum, 1500s–1800s octaedron, 1600s–1800s octoedron, 1800s– octahedron.

Origin: Of multiple origins. Partly a borrowing from Latin. Partly a borrowing from Greek. Etymons: Latin octaedrum; Greek ὀκτάεδρον, ὀκτάεδρος.

Etymology: < post-classical Latin octaedrum, octahedrum (4th cent.), and its etymon ancient Greek ὀκτάεδρον a three-dimensional figure having eight plane faces, use as noun of neuter singular of Hellenistic Greek ὀκτάεδρος eight-sided < ὀκτα- octa- comb. form + ἕδρα seat, base (see -hedron comb. form). Compare Middle French octocedron (1377), octehedre (1562), octaedre (1557), octohedre (1587), French †octahèdre (1691), octaèdre (1611 in Cotgrave), Italian ottaèdro (a1597), Spanish octaedro.On the forms in octo- see discussion at octa- comb. form. N.E.D. (1902) gives also the pronunciation (-he·drǫ̆n) /-ˈhɛdrən/ for the second element.

A three-dimensional figure having eight plane faces (usually, triangular faces); esp. (more fully regular octahedron) one of the five regular Platonic solids, a figure whose faces are eight equal equilateral triangles (such as is formed by two equal pyramids with equilateral faces on a square base). Also: a crystal or other object having this form.truncated octahedron: see truncated adj.

ΘΚΠ

the world > relative properties > number > geometry > shape or figure > [noun] > three-dimensional > penta-, hexa-, octa-, or dodecahedron

dodecahedron1570

octahedron1570

hexahedron1571

pentahedron1590

decahedron1828

1570 H. Billingsley tr. Comte de Candale in tr. Euclid Elements Geom. xiii. f. 406 An octohedron is deuided into two equall and like Pyramids.

1603 P. Holland tr. Plutarch Morals 1359 The Pyramis, the Cube, the Octaedron, Icosaedron & Dodecaedron.

1655 H. More Antidote against Atheism (ed. 2) App. ii. 297 There are Fiue regular Bodies..the Cube, the Tetraedrum, the Octaedrum, the Dodecaedrum, and the Eicosaedrum.

1656 T. Stanley Hist. Philos. II. v. 72 Fire, Earth, Water, and Aire; which foure the maker of the Universe..formed in a Pyramid, a Cube, an Octaedron, and an Icosaedron.

1742 Philos. Trans. 1739–40 (Royal Soc.) 41 247 It is universally allowed, that Salts in Crystallizing constantly retain one certain and determinate Figure; Sea-Salt concreting into Cubes, Vitriolic Salt into Rhomboidal Parallelepipeds, Alom into Octædrons.

1823 H. J. Brooke Familiar Introd. Crystallogr. 141 Octahedrons with rhombic bases.

1851 T. Wright & G. F. Richardson Introd. Geol. (new ed.) v. 76 If we take a cube and cut off all the eight corners till the original faces disappear, we shall make it an octohedron.

1880 E. Cleminshaw tr. C. A. Wurtz Atomic Theory 142 The nitrates of barium, strontium, and lead,..crystallise in octohedra.

1908 Philos. Trans. (Royal Soc.) A. 208 25 The planes are inclined to one another in practically the same way as the faces of a regular octahedron.

1953 Life 8 June 69/1 Three of the struts are riveted together into a triangle, four of these triangles then fitted together to form an octahedron then 10 octahedra riveted together to form a truss.

1989 W. Gellert et al. VNR Conc. Encycl. Math. (ed. 2) xi. 244 The regular octahedron is bounded by eight congruent equilateral triangles and twelve edges of equal length k.

This entry has been updated (OED Third Edition, March 2004; most recently modified version published online March 2022).

单词	octahedron
释义	octahedronn. Brit. /ˌɒktəˈhiːdrən/, U.S. /ˌɑktəˈhidrən/ Inflections: Plural octahedra, octahedrons. Forms: 1500s 1800s octohedron, 1500s–1700s octaedrum, 1500s–1700s octahedrum, 1500s–1800s octaedron, 1600s–1800s octoedron, 1800s– octahedron. Origin: Of multiple origins. Partly a borrowing from Latin. Partly a borrowing from Greek. Etymons: Latin octaedrum; Greek ὀκτάεδρον, ὀκτάεδρος. Etymology: < post-classical Latin octaedrum, octahedrum (4th cent.), and its etymon ancient Greek ὀκτάεδρον a three-dimensional figure having eight plane faces, use as noun of neuter singular of Hellenistic Greek ὀκτάεδρος eight-sided < ὀκτα- octa- comb. form + ἕδρα seat, base (see -hedron comb. form). Compare Middle French octocedron (1377), octehedre (1562), octaedre (1557), octohedre (1587), French †octahèdre (1691), octaèdre (1611 in Cotgrave), Italian ottaèdro (a1597), Spanish octaedro.On the forms in octo- see discussion at octa- comb. form. N.E.D. (1902) gives also the pronunciation (-he·drǫ̆n) /-ˈhɛdrən/ for the second element. A three-dimensional figure having eight plane faces (usually, triangular faces); esp. (more fully regular octahedron) one of the five regular Platonic solids, a figure whose faces are eight equal equilateral triangles (such as is formed by two equal pyramids with equilateral faces on a square base). Also: a crystal or other object having this form.truncated octahedron: see truncated adj. ΘΚΠ the world > relative properties > number > geometry > shape or figure > [noun] > three-dimensional > penta-, hexa-, octa-, or dodecahedron dodecahedron1570 octahedron1570 hexahedron1571 pentahedron1590 decahedron1828 1570 H. Billingsley tr. Comte de Candale in tr. Euclid Elements Geom. xiii. f. 406 An octohedron is deuided into two equall and like Pyramids. 1603 P. Holland tr. Plutarch Morals 1359 The Pyramis, the Cube, the Octaedron, Icosaedron & Dodecaedron. 1655 H. More Antidote against Atheism (ed. 2) App. ii. 297 There are Fiue regular Bodies..the Cube, the Tetraedrum, the Octaedrum, the Dodecaedrum, and the Eicosaedrum. 1656 T. Stanley Hist. Philos. II. v. 72 Fire, Earth, Water, and Aire; which foure the maker of the Universe..formed in a Pyramid, a Cube, an Octaedron, and an Icosaedron. 1742 Philos. Trans. 1739–40 (Royal Soc.) 41 247 It is universally allowed, that Salts in Crystallizing constantly retain one certain and determinate Figure; Sea-Salt concreting into Cubes, Vitriolic Salt into Rhomboidal Parallelepipeds, Alom into Octædrons. 1823 H. J. Brooke Familiar Introd. Crystallogr. 141 Octahedrons with rhombic bases. 1851 T. Wright & G. F. Richardson Introd. Geol. (new ed.) v. 76 If we take a cube and cut off all the eight corners till the original faces disappear, we shall make it an octohedron. 1880 E. Cleminshaw tr. C. A. Wurtz Atomic Theory 142 The nitrates of barium, strontium, and lead,..crystallise in octohedra. 1908 Philos. Trans. (Royal Soc.) A. 208 25 The planes are inclined to one another in practically the same way as the faces of a regular octahedron. 1953 Life 8 June 69/1 Three of the struts are riveted together into a triangle, four of these triangles then fitted together to form an octahedron then 10 octahedra riveted together to form a truss. 1989 W. Gellert et al. VNR Conc. Encycl. Math. (ed. 2) xi. 244 The regular octahedron is bounded by eight congruent equilateral triangles and twelve edges of equal length k. This entry has been updated (OED Third Edition, March 2004; most recently modified version published online March 2022). < n.1570
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