Triassic

adjective

Tri·​as·​sic trī-ˈa-sik 

: of, relating to, or being the earliest period of the Mesozoic era or the corresponding system of rocks marked by the first appearance of the dinosaurs see Geologic Time Table

Triassic noun

Examples of Triassic in a Sentence

Recent Examples on the Web

The ecology and geography of temnospondyl recovery after the Permian – Triassic mass extinction Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. —Paul Smaglik, Discover Magazine, 4 Mar. 2025

Standing near the hulking Megalosaurus, which dates from the Middle Jurassic period, Todd points out Cretaceous and Triassic specimens on either side of the beast. —Yannic Rack, Smithsonian Magazine, 29 Aug. 2023

Only after the end-Triassic mass extinction, in the Jurassic, did dinosaurs start to truly flourish—before that, the world saw a very different cast of ruling reptiles. —Riley Black, Smithsonian Magazine, 22 Mar. 2023

Word History

Etymology

International Scientific Vocabulary, from Latin trias triad; from the three subdivisions of the European Triassic — more at triad

First Known Use

1841, in the meaning defined above

Rhymes for Triassic

• actinic
• agnatic
• bailiwick
• bolshevik
• candlestick
• chloritic
• deontic
• firebrick
• herpetic
• judaic
• lunatic
• orthotic

Kids Definition

Triassic

adjective

Tri·​as·​sic trī-ˈas-ik 

: of, relating to, or being the earliest period of the Mesozoic era of geological history marked by the first appearance of dinosaurs

also : relating to the corresponding system of rocks see geologic time

Triassic noun