Definition of ganglion

• n. - A mass or knot of nervous matter, including nerve cells, usually forming an enlargement in the course of a nerve.
• n. - A node, or gland in the lymphatic system; as, a lymphatic ganglion.
• n. - A globular, hard, indolent tumor, situated somewhere on a tendon, and commonly formed by the effusion of a viscid fluid into it; -- called also weeping sinew.