Hȳ'le-o-sȧur', n.

n. [Gr. ὑλαῖον, belonging to a wood, from ὕλη, wood, and σαῦρος, lizard.] (Palæon.) An extinct animal, of gigantic size, which united in its structure the osteology of the crocodile with that of the lizard, found in the Wealden formation, England.