found:Henderson's dict. of biol. terms, 1979(Invertebrata, invertebrates: a general term for all animal groups except the vertebrates, i.e. all animals without a backbone)
found:Britannica micro.(invertebrate: any animal that lacks a vertebral column. The taxonomic term Invertebrata, formerly used in contrast to Vertebrata (still a valid subphylum name), has no validity in modern classifications.)