WordReference Random House Unabridged Dictionary of American English © 2026
ar•cho•saur
(är′kə sôr′),USA pronunciation n.
ar′cho•sau′ri•an, adj.
- Paleontology, Reptilesany reptile of the subclass Archosauria, including the dinosaurs, pterosaurs, and crocodilians and characterized by two pairs of openings in the temporal region of the skull.
- Neo-Latin Archosaurus, taken as singular of Archosauria, equivalent. to Greek archo-, combining form of archós ruler, chief + saûr(os) -saur + Neo-Latin -ia -ia
- 1965–70