Tyrannosaurus rex

American  

[ti-ran-uh-sawr-uhs reks, tahy‐] / tɪˌræn əˈsɔr əs ˈreks, taɪ‐ /

Also T. rex

noun

1. tyrannosaur.

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Tyrannosaurus rex Cultural  

1. A large, carnivorous (see carnivore) dinosaur that walked on two legs. Its name is from the Greek words meaning “tyrant” and “lizard” and the Latin word for “king.”

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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.

Etymology

Origin of Tyrannosaurus rex

First recorded in 1905–10; New Latin Tyrannosaurus, the genus name; tyrannosaur ( def. ) + Latin rex “king”; rex ( def. )

Example Sentences

A remarkably complete tyrannosaur skeleton has brought new clarity to one of paleontology's longest debates: whether Nanotyrannus was its own species or merely a young Tyrannosaurus rex.

From Science Daily • Nov. 2, 2025

It's nearly 10:00 pm on Friday night, and a group of children shine their flashlights on the imposing skeleton of a Tyrannosaurus rex.

From Barron's • Oct. 25, 2025

David Boyle set his sights on the 39-foot Tyrannosaurus rex, priced at $2,700 and advertised as “slightly used well loved!”

From The Wall Street Journal • Oct. 23, 2025

Running Nov. 1 to Jan. 31, the exhibit will feature a broad array of reptiles, ranging from the 6-foot-long Australovenator to a nearly 30-foot-long Tyrannosaurus rex.

From Los Angeles Times • Sep. 16, 2025

I’m not even sure why Crenshaw was a cat, and not a dog or an alligator or a Tyrannosaurus rex with three heads.

From "Crenshaw" by Katherine Applegate