'Plesiosaurus' definitions:
Definition of 'plesiosaurus'
(from WordNet)
noun
Extinct marine reptile with a small head on a long neck a short tail and four paddle-shaped limbs; of the Jurassic and Cretaceous [syn: plesiosaur, plesiosaurus]
Definition of 'Plesiosaurus'
From: GCIDE
- Plesiosaurus \Ple`si*o*sau"rus\, n.; pl. Plesiosauri. [NL., fr. Gr ? near + ? a lizard.] (Paleon.) 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. [1913 Webster]