centrosome n 1: small region of cytoplasm adjacent to the nucleus; contains the centrioles and serves to organize the microtubules [syn: {centrosome}, {central body}]
Centrosome \Cen"tro*some`\, n. [Gr. ? center + -? the body.] (Biol.) A peculiar rounded body lying near the nucleus of a cell. It is regarded as the dynamic element by means of which the machinery of cell division is organized. [1913 Webster]