/truy as"ik/ , Geol.
adj.
1. noting or pertaining to a period of the Mesozoic Era, occurring from 230 to 190 million years ago and characterized by the advent of dinosaurs and coniferous forests. See table under geologic time .
n.
2. Also, Trias /truy"euhs/ the Triassic Period or System.
[ 1835-45; Trias the three-part series of strata characterizing the period ( triás; see TRIAD) + -IC ]