‖ centrum
(ˈsɛntrəm)
[L. centrum centre of rotation, etc., a. Gr. κέντρον sharp point, a goad, a peg, the stationary point of a pair of compasses; f. same root as κεντέ-ειν to prick, goad, stab, etc.]
1. The Latin word for centre, used technically in Animal Phys.: The body of a vertebra; the solid part to which the arches and processes are attached.
| 1854 R. Owen in Circ. Sc. (1865) II. 62/2 The centrums coalesce. 1869 Gillmore Rept. & Birds Introd. 5 Free vertebræ, forming a series of separate centrums, deeply cupped at both ends. 1870 Rolleston Anim. Life 5 The articulate ends of their centra. 1871 Darwin Desc. Man I. i. 29. |
2. The place from which an earthquake originates.
| 1887 Nature 31 Oct. 657 The determination of earthquake origins, the depth of ‘centrums’, [etc.]. 1938 L. D. Leet Practical Seismol. viii. 280 With growth of the concept that ordinarily the focus was actually at a finite depth below the surface, the term ‘centrum’ was modified to hypocenter, signifying the deep center, or focus; and epicenter, or point on the surface vertically above the focus. |