Tyrannosaurus rex
Americannoun
Usage
What is a Tyrannosaurus rex? Tyrannosaurus rex was 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.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of Tyrannosaurus rex
First recorded in 1905–10; New Latin Tyrannosaurus, the genus name; see tyrannosaur ( def. ) + Latin rex “king”; see 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.
A Tyrannosaurus rex skeleton nicknamed "Gus" sold Tuesday for $50.1 million at Sotheby's in New York, making it the most valuable dinosaur fossil bought at auction after a 10-minute battle between seven bidders.
From Barron's ● Jul. 14, 2026
One of the world's most complete Tyrannosaurus rex skeletons, nicknamed "Gus," was showcased Wednesday at Sotheby's auction house in New York ahead of its sale later this month.
From Barron's ● Jul. 1, 2026
More than a century after Tyrannosaurus rex was first described by scientists, the giant predator continues to reveal new surprises.
From Science Daily ● Jun. 22, 2026
"This lets us be confident in keeping the name Nanotyrannus, because this animal is clearly not on a growth path to becoming a Tyrannosaurus rex."
From Science Daily ● Apr. 15, 2026
From the way his pockets were sticking out it looked like he had one Tyrannosaurus rex and one triceratops.
From "The Watsons Go to Birmingham" by Christopher Paul Curtis
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.
