Tyrannosaurus rex


Ty·​ran·​no·​sau·​rus rex tə-ˌra-nə-ˈsȯr-əs-ˈreks How to pronounce Tyrannosaurus rex (audio)
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 Among them are raptors, a tyrannosaurus, and a brachiosaurus rising almost 16 feet into the sky. Chris Schalkx, Travel + Leisure, 21 Aug. 2023 There’s the tyrannosaurus hunting the triceratops. Cody Cassidy, Wired, 9 Apr. 2021 The tyrannosaurus rex, for instance, had longer and larger arms than abelisaurids, but don't let their puny arms fool you. Jordan Mendoza, USA TODAY, 20 Feb. 2022 Like a blonde tyrannosaurus in a very fancy turtleneck. Jodi Walker, EW.com, 29 May 2020 Most scientists now believe that birds are theropods, dinosaurs of a group that included tyrannosaurus and spinosaurus, but that birds were on their own evolutionary branch from a common ancestor. Lucas Joel, New York Times, 11 Mar. 2020 The dinosaur, named Thanatotheristes degrootorum, is the first new tyrannosaurus species to be discovered in Canada in 50 years. Li Cohen, CBS News, 10 Feb. 2020 Giant brontosauruses, velociraptors, and multiple tyrannosaurus can be seen outside on the business' 8 acres and within its giant facility. Fernando Alfonso Iii, Houston Chronicle, 20 June 2018 March is definitely coming in like a lion, or maybe a tyrannosaurus? David Streit, Washington Post, 1 Mar. 2018 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'Tyrannosaurus rex.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


New Latin

First Known Use

1905, in the meaning defined above

Time Traveler
The first known use of Tyrannosaurus rex was in 1905

Dictionary Entries Near Tyrannosaurus rex

Cite this Entry

“Tyrannosaurus rex.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Tyrannosaurus%20rex. Accessed 25 Sep. 2023.

Last Updated: - Definition revised
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