hadrosaur|ˈhædrəʊsɔː(r)| [ad.mod.L. Hadrosaurus (name of the genus), f.Gr. ἁδρό-ς thick, stout + σαῦρος (= σαύρα) lizard.] A genus of gigantic fossil saurian reptiles found in North America. 1877Le Conte Elem.Geol. iii. (1879) 467 The Hadrosaur from New Jersey was twenty-eight feet long.