an animal lacking a backbone, such as an arthropod, mollusc, annelid, coelenterate, etc. The invertebrates constitute an artificial division of the animal kingdom, comprising 95 per cent of animal species and about thirty different phyla.
denoting an invertebrate or relating to the invertebrates as a group.
irresolute; spineless
having a particular habit, activity, or interest that is long-established and unlikely to change
(of a feeling or habit) long-established and unlikely to change