Ganglion (noun)

1. A structure in the nervous system that contains a group of nerve cell bodies and serves as a relay point for nerve impulses.
2. A cystic tumor, usually benign, that develops on a tendon or joint capsule.
3. A mass of nerve tissue that resembles a knot, especially on the back of the wrist or foot.

Origin:

From late latin 'ganglion', meaning 'a tumor', from greek 'ganglion', meaning 'knot' or 'swelling'.

Examples:

1. The dorsal root ganglion is a cluster of nerve cell bodies in the spinal cord.
2. Ganglia are also found in the autonomic nervous system.
3. The patient was diagnosed with a ganglion cyst on their wrist.
4. My doctor told me the bump on the back of my foot is a ganglion.
5. The ganglion was causing severe pain and inflammation in her wrist.