- a variation of Tyrannosaurus rex.
T. rex
Americannoun
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
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
That improvement persuaded L.A.'s Natural History Museum to provide tiny portions of two teeth belonging to Thomas the T. rex, the most complete of the towering tyrannosaur skeletons displayed in the museum's dinosaur hall.
From Science Daily ● Sep. 20, 2026
The finding supports the picture of T. rex as an active predator or scavenger with a relatively fast metabolism rather than a sluggish animal that depended heavily on basking in the sun.
From Science Daily ● Sep. 20, 2026
Museum paleontologists excavated some 70% of Thomas’s fossilized skeleton in the early 2000s, making it one of the most complete T. rex specimens ever found.
From Los Angeles Times ● Sep. 16, 2026
“Run, Denise!” is the kind of unhelpful remark, delivered by Greg when his wife is already well aware that a T. rex is bearing down on her, that defines the dialogue.
From The Wall Street Journal ● Aug. 13, 2026
He could smile at a T. rex, and next thing, they’d be making plans to have a burger together.
From "I Survived Hurricane Katrina, 2005" by Lauren Tarshis
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
