Plesiosaurus
Pronunciation : Ple`si*o*sau"rus
Part of Speech : n.;
Etymology : [NL., fr. Gr (Paleon.)
Definition : Defn: A genus of large extinct marine reptiles, having a very long neck, a small head, and paddles for swimming. It lived in the Mesozoic age.
pl. Plesiosauri.
Source : Webster's Unabridged Dictionary, 1913