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 forms
notochordal (ˌnotoˈchordal)
adjective
notochord in American English
(ˈnoʊtəˌkɔrd)
noun
1.
an elongated, rod-shaped structure composed of cells, forming the primitive supporting axis of the body in the lowest chordates and lying between the digestive tract and the central nervous system
2.
a similar structure in the embryonic stages of higher vertebrates, which later is surrounded and replaced by the vertebral column