1. (n.) A mass or knot of nervous matter, including nerve cells, usually forming an enlargement in the course of a nerve.

2. (n.) A node, or gland in the lymphatic system; as, a lymphatic ganglion.

3. (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.

afferent neuron autonomic nervous system axon brain center of activity central nervous system cerebral cortex craniosacral nervous system dendrite effector organ efferent neuron gray matter internuncial neuron medullary sheath nerve nerve center nerve trunk nervous system neuron peripheral nervous system plexus sensorium sensory area sensory cell solar plexus spinal cord synapse thoracolumbar nervous system vital center white matter