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noun ple·si·o·saur \ˈplē-sē-ə-ˌsȯr, -zē-\

Definition of plesiosaur

  1. :  any of an order or suborder (Plesiosauria) of large carnivorous marine reptiles of the Mesozoic with dorsoventrally flattened bodies and limbs modified into flippers

Origin and Etymology of plesiosaur

ultimately from Greek plēsios close (akin to Greek pelas near) + sauros lizard

First Known Use: 1839

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