centrum, i, n., = κέντρον (a prickle, sharp point).
I Centrum circini, the stationary foot of the compasses , around which the other is carried in making a circle , Vitr. 3, 1; 9, 5.—Hence,
II Meton.
A The middle point of a circle , the centre , Vitr. 3, 1; 9, 1; Plin. 2, 15, 13, § 63; 2, 19, 17, § 81 et saep.—In plur.: solis terraeque centra, Plin. 18, 29, 69, § 281 (in Cic. Tusc. 1, 17, 40, used as a Greek word).—
B A kernel , a hard knot in the interior of wood , precious stones , etc., Plin. 16, 39, 76, § 198; 37, 2, 10, § 28; 37, 9, 39, § 120 al.