What is "chorda dorsalis"

Notochord \No"to*chord\, n. [Gr. nw^ton the back + E. chord.] (Anat.) 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 vertebr[ae] and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of Ectoderm.

n. (context anatomy English) notochord