noun Embryology.
  1. a rodlike cord of cells that forms the chief axial supporting structure of the body of the lower chordates, as amphioxus and the cyclostomes, and of the embryos of the vertebrates.

Origin of notochord

1840–50; noto- + chord1 (in the sense of ‘a cordlike anatomical structure’)
Related formsno·to·chord·al, adjectivesub·no·to·chord·al, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for notochord

Historical Examples of notochord

British Dictionary definitions for notochord


  1. a fibrous longitudinal rod in all embryo and some adult chordate animals, immediately above the gut, that supports the body. It is replaced in adult vertebrates by the vertebral column
Derived Formsnotochordal, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for notochord

1848, coined in English by English anatomist Sir Richard Owen (1804-1892) from chord + comb. form of Greek noton "back," from PIE *not- "buttock, back" (cf. Latin natis "buttock," sopurce of Italian, Spanish nalga, Old French nache "buttock, butt").

Online Etymology Dictionary, © 2010 Douglas Harper

notochord in Medicine


  1. A flexible rodlike structure that forms the main support of the body in the lowest chordates; a primitive backbone.
  2. A similar structure in embryos of higher vertebrates, from which the spinal column develops.
Related formsno′to•chordal adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

notochord in Science


  1. A flexible rodlike structure that forms the main support of the body in all chordates during some stage of their development. In vertebrates, the notochord develops into a true backbone in the embryonic phase. Primitive chordates, such as lancelets and tunicates, retain a notochord throughout their lives.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.