from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A flexible rodlike structure that forms the main support of the body in the lowest chordates, such as the lancelet; a primitive backbone.
- n. A similar structure in embryos of higher vertebrates, from which the spinal column develops.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A flexible rodlike structure that forms the main support of the body in the lowest chordates; a primitive spine
- n. A similar structure found in the embryos of vertebrates from which the spine develops
from the GNU version of the Collaborative International Dictionary of English
- n. An elastic cartilagelike rod which is developed beneath the medullary groove in the vertebrate embryo, and constitutes the primitive axial skeleton around which the centra of the vertebræ and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of ectoderm.
from The Century Dictionary and Cyclopedia
- n. The chorda dorsalis or primitive backbone: a fibrocellular or cartilaginous rod-like structure which is developed in vertebrates as the basis of the future spinal column, and about which the bodies of the future vertebræ are formed.
- n. A vestigial structure, representing a very ancient form of alimentary canal not in itself a part of the skeleton.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates
Greek nōton, back + chord2.(American Heritage® Dictionary of the English Language, Fourth Edition)