T. rex

American  

[tee reks] / ˈti ˈreks /

noun

1. tyrannosaur.

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Usage

What is a T. rex? T. rex is short for Tyrannosaurus rex, a giant, meat-eating dinosaur that walked on two legs and had a long tail and a big head with sharp teeth (and, yes, two little arms). The name Tyrannosaurus rex comes from the Greek words tyranno (“tyrant”) and saurus (“lizard”) and the Latin word rex (“king”). So, Tyrannosaurus rex means something like “king of the tyrant lizards.” It is commonly called T. rex for short. The name is fitting: Tyrannosaurus rex is one of the largest land predators that has ever lived. It was the largest of the tyrannosaurs, reaching a length of 47 feet (14. 3 m) or more. People often list the T. rex as their favorite dinosaur, and its popularity has grown through many pop culture depictions, such as its appearances in the Jurassic Park series of movies and books. However, to be scientifically precise about it, the T. rex lived during the Late Cretaceous period, about 90–65 million years ago, around the end of the age of dinosaurs.

Etymology

Origin of T. rex

First recorded in 1980–85; abbreviation of Tyrannosaurus rex ( def. )

Example Sentences

Estimates suggest Nanotyrannus reached about 18 feet in length, making it significantly smaller than a full-grown T. rex, which could exceed 40 feet.

From Science Daily • Apr. 15, 2026

If anything, after a few days spent dipping my T. rex hands into the cool primordial sludge of the dinosaur fandom, Panella’s sentiment feels like an understatement.

From Salon • Apr. 12, 2026

A tridimensional T. rex protrudes from Iñaki Godoy’s head while he holds a small plush toy of Monkey D. Luffy, the character who changed his life forever.

From Los Angeles Times • Mar. 10, 2026

The findings also hint that some fossils previously classified as T. rex could actually belong to different species or represent other biological differences.

From Science Daily • Mar. 5, 2026

We saw SUE the T. rex at the Field Museum, and Seurat’s people in the park, painted from tiny dots, at the Art Institute.

From "The First Rule of Punk" by Celia C. Pérez