notochord
no.to.chord \'no-t-*-.ko.(*)rd\ \.no-t-*-'ko.rd-*l\ n [not- + L chorda cord - more at CORD] : a longitudinal flexible rod of cells that in the lowest chordates (as am phioxus and lampreys) and in the embryos of the higher vertebrates forms the supporting axis of the body - no.to.chord.al aj