Wordnet 3.0
NOUN (1)
1. 
 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; 
[syn: spinal cord, medulla spinalis]
WordNet (r) 3.0 (2006):
medulla spinalis
    n 1: 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 [syn: spinal cord, medulla spinalis]