reptile - any cold-blooded vertebrate of the class Reptilia including tortoises turtles snakes lizards alligators crocodiles and extinct formscraniate, vertebrate - animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium class Reptilia, Reptilia - class of cold-blooded air-breathing vertebrates with completely ossified skeleton and a body usually covered with scales or horny plates; once the dominant land animals anapsid, anapsid reptile - primitive reptile having no opening in the temporal region of the skull; all extinct except turtles Diapsida, subclass Diapsida - used in former classifications to include all living reptiles except turtles; superseded by the two subclasses Lepidosauria and Archosauria |