Tyrannosaurus rex

noun

Ty·​ran·​no·​sau·​rus rex tə-ˌra-nə-ˈsȯr-əs-ˈreks 

(ˌ)tī-

variants or Tyrannosaurus Rex or less commonly Tyrannosaurus or tyrannosaurus or tyrannosaurus rex

plural Tyrannosaurus rexes or Tyrannosaurus Rexes also Tyrannosauruses or tyrannosauruses or tyrannosaurus rexes

: a massive North American bipedal tyrannosaurid dinosaur (Tyrannosaurus rex) of the late Cretaceous with a large skull, heavy tail, and reduced forelimbs having two clawed digits : tyrannosaur sense 1

Tyrannosaurus rex was … one of the biggest meat-eaters ever. It was over 40 feet tall, and weighed up to 7 tons!

—Wendy Larson

A study of the running ability of Tyrannosaurus Rex … suggests that the king of the prehistoric jungle wasn't quite the speedster we once thought.

—Andrea Dorfman et al.

During this period, many groups of dinosaurs, including the fearsome tyrannosaurus and the three-horned triceratops, reached their greatest size, 12 meters (40 feet) and 9 meters (30 feet) long, respectively.

—Joseph Wallace

… in a room full of Tyrannosaurus rexes I meet museum volunteers … who are using brushes and tiny picks on fossils in an area where people can watch and ask questions.

—Mel White

True, there may no longer be actual tyrannosauruses running amok, but there are still dinosaur descendants hanging around, and they may even be in your backyard: birds, of course!

—Emily Graham

called also T. rex

Examples of Tyrannosaurus rex in a Sentence

Recent Examples on the Web

Using Tyrannosaurus rex as a model, paleontologists have estimated that much more massive dinosaurs are still awaiting discovery. —Riley Black, Smithsonian Magazine, 16 Dec. 2024

All the chess pieces are shaped like the Tyrannosaurus rex, Spinosaurus, Dilophosaurus, Velociraptor, Brachiosaurus, and Pteranodon. —Christopher Murray, Fox News, 12 Dec. 2024

The last holder of that title was the fossil assemblage of a Tyrannosaurus rex named Stan. —Shi En Kim, Smithsonian Magazine, 9 Dec. 2024

Stan, a remarkably complete Tyrannosaurus rex fossil, sold for $31.8 million at a Christie's auction in 2020, setting a world record for any dinosaur fossil at the time. —Paul Du Quenoy, Newsweek, 9 Dec. 2024

Apex's sale beat that of Stan, a Tyrannosaurus rex that previously held the title of most expensive dinosaur after fetching $31.8 million at auction in 2020. —Claire Thornton, USA TODAY, 6 Dec. 2024

The tyrannosaurs living here likely would have been about a third of the size of their more famous North American cousin Tyrannosaurus rex. —Laura Baisas, Popular Science, 5 Dec. 2024

Does reading about one of the most common birds on the planet sharing ancestry with a fearsome predator like the Tyrannosaurus rex reinforce a belief that animals are just as fascinating as humans? —Scott Travers, Forbes, 4 Dec. 2024

Some would say the most popular dinosaur predator of all time is the Tyrannosaurus rex. —Sara Novak, Discover Magazine, 26 Nov. 2024

Word History

Etymology

New Latin

First Known Use

1905, in the meaning defined above