The Collaborative International Dictionary of English v.0.48:

Chordata \Chor*da"ta\, n. pl. [NL., fr. L. chorda cord.] (Zool.)
   A comprehensive division of animals including all Vertebrata
   together with the Tunicata, or all those having a dorsal
   nervous cord.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Chordata
    n 1: comprises true vertebrates and animals having a notochord
         [syn: Chordata, phylum Chordata]