脊索 jǐsuǒ notochord Definitions Defs Origin Strokes Stroke Words Sentences Sents 脊索动物 jǐsuǒdòngwù chordate Animal belonging to the phylum Chordata, characterized by having a notochord at some stage of development; includes tunicates, lancelets, and all vertebrates.脊索动物门 jǐsuǒdòngwùmén Chordata the Chordata phylum of animals, which includes all vertebrates