Pronunciation: (gang'glē-un),[key] —n., —pl.-gli•aPronunciation: (-glē-u),[key]-gli•ons. 1. Anat. a. a mass of nerve tissue existing outside the central nervous system.
b. any of certain masses of gray matter in the brain, as the basal ganglia.
2. Pathol.a cyst or enlargement in connection with the sheath of a tendon, usually at the wrist.
3. a center of intellectual or industrial force, activity, etc.