ganglion

noun

• (neuroanatomy)
• An encapsulated collection of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber.
• Any of certain masses of gray matter in the central nervous system, as the basal ganglia.
• (transferred sense) A centre of intellectual or industrial force, activity, etc.
• (pathology) A benign cystic tumour on a tendon sheath or joint capsule.