Real Dictionary

ceratopsian in American English
any of a suborder (Ceratopsia) of horned ornithischian dinosaurs of the Cretaceous with a beaklike snout and a bony crest at the back of the head
of the ceratopsians
noun: any of several four-footed, herbivorous dinosaurs of the suborder Ceratopsia, of the late Cretaceous Period, having an enlarged skull with a beak, a large perforated frill at the back, and, in some species, one or three horns

ceratopsian in British English
adjective: resembling or belonging to the Ceratopsia, a suborder of herbivorous dinosaurs characterized by their parrot-like beaks, horns, and neck frills
noun: a dinosaur of the suborder Ceratopsia