horned dinosaur vs ceratopsian

horned dinosaur and ceratopsian both are nouns.

Word	Noun	Adjective	Verb	Adverb
horned dinosaur	Yes	No	No	No
ceratopsian	Yes	No	No	No

As nouns, horned dinosaur and ceratopsian are synonyms defined as:

horned dinosaur and ceratopsian: any of several four-footed herbivorous dinosaurs with enormous beaked skulls; of the late Cretaceous in North America and Mongolia

horned dinosaur (noun)	ceratopsian (noun)
any of several four-footed herbivorous dinosaurs with enormous beaked skulls; of the late Cretaceous in North America and Mongolia	any of several four-footed herbivorous dinosaurs with enormous beaked skulls; of the late Cretaceous in North America and Mongolia