From Greek 'kéntron' (a sharp point, a goad), the word originally named the stationary needle of a compass — the prick mark at the middle of a circle.
The middle point of a circle or sphere, equidistant from every point on the circumference or surface; the most important part of an activity or place; a point around which something revolves.
English 'center' comes via Old French 'centre' from Latin 'centrum' (the fixed point of a pair of compasses; the center of a circle), borrowed from Greek 'kéntron' (κέντρον), which originally meant 'a sharp point, a goad, a sting.' The Greek word derives from 'kenteîn' (to prick, to sting). The semantic leap is from the sharp stationary point of a compass — the point that pricks the surface — to the geometric center of the circle that the compass draws