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 WordNet 3.0 & Open English WordNet

The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column of vertebrate animals. Wikipedia

Long, thin, tubular structure made up of nervous tissue Wikidata

A thick, whitish cord of nerve tissue which is a major part of the vertebrate central nervous system. It extends from the brainstem down through the spine, with nerves branching off to various parts of the body. It is enclosed in and protected by the vertebral column. OmegaWiki

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. Wiktionary

Thick, whitish cord of nerve tissue. Wiktionary (translation)