Main Entry: ich·thyo·saur

Pronunciation: \ˈik-thē-ə-ˌsȯr\

Function: noun

Etymology: ultimately from Greek ichthy- + sauros lizard

Date: 1830

: any of an order (Ichthyosauria) of extinct marine reptiles of the Mesozoic specialized for aquatic life by a streamlined body with a long snout, limbs reduced to small fins for steering, and a large lunate caudal fin

— ich·thyo·sau·ri·an \ˌik-thē-ə-ˈsȯr-ē-ən\ adjective or noun