ganglion

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Anatomy A group of nerve cells forming a nerve center, especially one located outside the brain or spinal cord.
2. n. A center of power, activity, or energy.
3. n. Pathology A benign cystic lesion resembling a tumor, occurring in a tendon sheath or joint capsule.

Century Dictionary and Cyclopedia

1. n. An enlargement in the course of a nerve, containing or consisting of a collection of ganglion-cells; any assembly of ganglion-cells. The nervous system of invertebrates generally, and the sympathetic nervous system of vertebrates, consists essentially of a chain or series of ganglia connected by commissures, giving off filaments in various directions, forming plexuses or networks around principal viscera, blood-vessels, and other important organs. Some of the larger sympathetic ganglia are also called plexuses; thus, the semilunar ganglia of the abdomen form the solar plexus. In the cerebrospinal nervous system of vertebrates, ganglia regularly occur on the posterior or sensory roots of the spinal nerves. There are likewise ganglia upon some of the motor or sensorimotor cranial nerves, as the vagus, fifth, and facial. All the masses of gray neurine in the brain are also ganglia, as the optic thalami, corpora quadrigemina, corpora striata, etc.; even the general mass of cortical gray matter, both of the cerebrum and of the cerebellum, constitutes a great ganglion. The principal ganglia have special names. See the phrases below.
2. n. A knot or enlargement on a lymphatic; a lymphatic gland. See cut under lymphatic.—
3. n. In pathology:
4. n. An encysted enlargement in connection with the sheath of a tendon: called simple ganglion.
5. n. Inflammation, with effusion into one or more sheaths of tendons: called diffuse ganglion.
6. n. An enlarged bursa.
7. n. In botany, the mycelium of certain fungals.
8. n. The superior ganglion, or ganglion of the root of the pneumogastric nerve, in its passage through the jugular foramen.
9. n. The lower ganglion, or ganglion of the trunk. Also vagus ganglion.
10. n. Same as Gasserian ganglion.
11. n. In cephalopods, same as stellate ganglion .
12. n. In cephalopods, a large flat ganglion lying on the inner surface of the mouth, in front of the gill.

Wiktionary

1. n. anatomy A mass of tissue.
2. n. neuroanatomy A cluster of interconnecting nerve cells outside the brain.
3. n. by extension A centre of power or authority

GNU Webster's 1913

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.
3. n. (Med.) 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.

WordNet 3.0

1. n. an encapsulated neural structure consisting of a collection of cell bodies or neurons