[di.no.saur] n [NL Dinosaurus, genus name, fr. Gk deinos terrifying + sauros lizard--more at dire] (1841) 1: any of a group (Dinosauria) of extinct chiefly terrestrial carnivorous or herbivorous reptiles of the Mesozoic era
2: any of various large extinct reptiles other than the true dinosaurs
3: one that is impractically large, out-of-date, or obsolete -- di.no.sau.ri.an adj