Triassic

[traɪ'æsɪk]

(noun.) from 230 million to 190 million years ago; dinosaurs, marine reptiles; volcanic activity.

(adj.) of or relating to or denoting the first period of the Mesozoic era .

Checker: Valerie--From WordNet

(a.) Of the age of, or pertaining to, the Trias.

(n.) The Triassic formation.

Checker: Thelma