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.
A person's brain.
Used other than figuratively or idiomatically: see upper, storey.