from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The thick, whitish cord of nerve tissue that extends from the medulla oblongata down through the spinal column and from which the spinal nerves branch off to various parts of the body.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A thick, whitish cord of nerve tissue which is a major part of the vertebrate central nervous system. It extends from the brain stem down through the spine, with nerves branching off to various parts of the body.
from the GNU version of the Collaborative International Dictionary of English
- adj. the great nervous cord extending backward from the brain along the dorsal side of the spinal column of a vertebrate animal, and usually terminating in a threadlike appendage called the filum terminale; the spinal, or vertebral, marrow; the myelon. The nervous tissue consists of nerve fibers and nerve cells, the latter being confined to the so-called gray matter of the central portions of the cord, while the peripheral white matter is composed of nerve fibers only. The center of the cord is traversed by a slender canal connecting with the ventricles of the brain.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a major part of the central nervous system which conducts sensory and motor nerve impulses to and from the brain; a long tubelike structure extending from the base of the brain through the vertebral canal to the upper lumbar region
Sorry, no etymologies found.