n. A center. Specificallyn. In anatomy:n. The body of a vertebra: the solid piece to which the arches and some other parts are or may be attached.n. The basis or fundamental portion of one of the cranial segments, regarded as analogous to vertebræ. Thus, the basioccipital is the centrum of the occipital segment of the skull.n. In geology, the focus or place of origin of an earthquake.