notochord

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.

noun

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

n.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”). n.

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.

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.