- 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.
“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
They and the other dinosaurs — a T. rex, an armored ankylosaurus, a sight-gag-worthy giant snake — adapt to the 20th century as comfortably as coyotes, skulking through backyards in search of prey.
From Los Angeles Times ● Aug. 12, 2026
"Gus" is one of the world's most complete T. rex skeletons -- with 183 fossilized bones -- and was discovered on a cattle ranch in South Dakota in 2021.
From Barron's ● Jul. 14, 2026
They then spent a further three years documenting and reconstructing the T. rex back in the lab.
From BBC ● Jul. 11, 2026
I do my signature Dinosaur Walk, where I stomp around like a T. rex with Penny in my arms, which always seems to relax her.
From "They Both Die at the End" by Adam Silvera
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.
