<p><strong>Noun</strong></p><ul><li>Plural: ganglia, ganglions</li><li>Anatomy: A mass of nerve tissue existing outside the central nervous system.</li><li>Any of certain masses of gray matter in the brain, such as the basal ganglia.</li><li>Pathology: A cyst or enlargement in connection with the sheath of a tendon, usually at the wrist.</li><li>A center of intellectual or industrial force, activity, etc.</li></ul>