Webster's 1913 Dictionary
HADROSAURUS
Had `ro *sau "rus, n. Etym: [NL. , fr. Gr. "adro `s thick + say ^ros lizard. ] (Paleon.)
Defn: An American herbivorous dinosaur of great size, allied to the iguanodon. It is found in the Cretaceous formation.
New American Oxford Dictionary
hadrosaur
had ro saur |ˈhadrəˌsôr ˈhædrəˌsɔ (ə )r |(also hadrosaurus |ˌhadrəˈsôrəs |) ▶noun a large, herbivorous, mainly bipedal dinosaur of the middle to late Cretaceous period, with jaws flattened like the bill of a duck. Also called duck-billed dinosaur. [Family Hadrosauridae, infraorder Ornithopoda, order Ornithischia. ] DERIVATIVES had ro sau ri an adjective ORIGIN late 19th cent.: from modern Latin Hadrosaurus (genus name ), from Greek hadros ‘thick, stout ’ + sauros ‘lizard. ’
Oxford Dictionary
hadrosaur
hadrosaur |ˈhadrəsɔː | ▶noun a large herbivorous mainly bipedal dinosaur of the late Cretaceous period, with jaws flattened like the bill of a duck. Also called duck-billed dinosaur. ●Family Hadrosauridae, infraorder Ornithopoda, order Ornithischia. ORIGIN late 19th cent.: from modern Latin Hadrosaurus (genus name ), from Greek hadros ‘thick, stout ’ + sauros ‘lizard ’.
The Wordsmith Dictionary