Definition of: cerebellum

(ser′ə·bel′əm) noun plural ·bel·lums or ·bel·la (-bel′ə)
The massive, dorsally located organ of the central nervous system forming that part of the brain below and behind the cerebrum. It consists of a central lobe and two lateral lobes and acts as the coordination center of voluntary movements, posture, and equilibrium. [<L, dim. of cerebrum brain]
—cer′e·bel′lar adjective