Any of certain masses of gray matter in the central nervous system, as the basal ganglia.
An encapsulated collection of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber.
A centre of intellectual or industrial force, activity, etc.
A benign cystic tumour on a tendon sheath or joint capsule.
Literal brains as a general substance.
A collection of cell bodies and (usually) dendritic connections, in contrast to white matter.
Brains; a person's ability to think.