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Tyrannosaurus rex

American  
[ti-ran-uh-sawr-uhs reks, tahy‐] / tɪˌræn əˈsɔr əs ˈreks, taɪ‐ /
Also T. rex

noun

  1. tyrannosaur.


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.”


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; 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.

It lived between 100 and 120 million years ago - around 40 million years earlier than the tyrannosaurus rex - and is about twice the size of that creature.

From BBC • May 14, 2026

Earlier this year, the United States returned dinosaur fossils taken out of Mongolia, including the skull of an alioramus, a smaller version of a tyrannosaurus rex that lived 70 million years ago.

From Reuters • Nov. 20, 2023

As it moved through the toppled trees and standing brush, it mimicked the sound of a tyrannosaurus rex making its way through the jungle in a “Jurassic Park” movie.

From Washington Times • Jul. 18, 2020

Dealers also noted that the herbivorous stegosaurus lacks the “wow” factor of a meat-eater like tyrannosaurus rex.

From New York Times • Jun. 3, 2016

Cue the enormous Gorog, a skyscraping combination of tyrannosaurus rex and the twisted behemoth from Cloverfield.

From The Guardian • Oct. 6, 2010

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