spheroid, n. and a.
(ˈsfɪərɔɪd)
Also 7–9 sphæroid, 8 spheroide.
[ad. L. sphæroīdēs, ad. Gr. σϕαιροειδής, f. σϕαῖρα ball: see -oid. So F. sphéröde (1556), It. sferoide, Sp. and Pg. esferoide.]
A. n. A body approaching in shape to a sphere, esp. one formed by the revolution of an ellipse about one of its axes. oblate spheroid, prolate spheroid: see the adjs.
| 1664 Barrow in Rigaud Corr. Sci. Men (1841) II. 39 Were I to compute the portions of a sphere or spheroid, I should only use these rules, out of Archimedes. 1698 J. Keill Exam. Th. Earth (1734) 95 After the fashion of a broad spheroid which is generated by the rotation of a semi Ellipsis round its lesser Axis. 1777 Phil. Trans. LVII. 285 Conceive now a spherical surface..to be carried about with the revolving spheroid. 1829 Chapters Phys. Sci. 41 In all cases, the centre of gravity tends towards the centre of the terrestrial spheroid, or to a point very near to it. 1854 Murchison Siluria vi. 134 [Mudstone] has a tendency to run into large spheroids. 1881 Le Conte Sight 52 The form of a perfect eye is that of a spheroid of revolution about the optic axis. |
B. adj. = spheroidal a.
| 1767 Phil. Trans. LVIII. 32 As no two measurements..make the earth of the same spheroid figure. 1875 Cooke Fungi 62 Afterwards small sphæroid projections appear at certain points on the mycelium. 1884 Jefferies Red Deer iii. 42 The spheroid form concentrates more substance in a given measurement than any other. |