di·​no·​saur | \ˈdī-nə-ˌsȯr \

Definition of dinosaur 

1 : any of a group (Dinosauria) of extinct often very large chiefly terrestrial carnivorous or herbivorous reptiles of the Mesozoic era

2 : any of various large extinct reptiles (such as ichthyosaurs) other than the true dinosaurs

3 : one that is impractically large, out-of-date, or obsolete The factory is now a rusting dinosaur.

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Other Words from dinosaur

dinosaurian \ˌdī-​nə-​ˈsȯr-​ē-​ən \ adjective
dinosauric \-​ˈsȯr-​ik \ adjective

Synonyms for dinosaur


has-been, relic

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Examples of dinosaur in a Sentence

The old factory is now a rusting dinosaur. The character she plays is a dinosaur—a former beauty queen who is living in the past.

Recent Examples on the Web

The film is set in the ocean world but also travels to the Sahara desert, a Sicilian coastal town and a beach with small dinosaurs. Ellen Gamerman, WSJ, "The Movies to See This Holiday Season," 17 Nov. 2018 The creature's appearance has been described as resembling a plesiosaur, an ancient sea monster that died out with the dinosaurs. Fox News, "Loch Ness Monster: This is Scotland's plan if the fabled beast is caught," 10 July 2018 The movie picks up where the last movie ended, with dinosaurs rampaging through the fictional Isla Nublar. Fortune, "'Jurassic World: Fallen Kingdom' Continues Stomping on Its Box Office Competition," 1 July 2018 Because the filmmakers decided that the best thing to do with the rampaging digital dinosaurs was to bring them indoors. Derek Connolly, New York Times, "Review: ‘Jurassic World: Fallen Kingdom’ Brings the Gang Back. Sigh.," 20 June 2018 But despite our cultural obsession with dinosaurs, there is much to their story that has been left untold until now. Andrea Gawrylewski, Scientific American, "The Ultimate Dinosaur Biography, A Cosmological Caper and Other New Science Books," 1 Apr. 2018 From gallivanting with dinosaurs with Chris Pratt to fighting off aliens with Chloe Grace Moretz, Robinson is no stranger to the big screen. Ale Russian, PEOPLE.com, "Love, Simon Star Nick Robinson Says Movie Helped Him Connect with Gay Brother," 14 Mar. 2018 Like cute long-sleeve t-shirts with dinosaurs on them, for example. Sarah Smith, Redbook, "Should We Ditch "Work-Life Balance" for "Work-Life Blend?"," 9 Sep. 2013 The product was originally at least partly positioned as a home theater PC, but those devices have gone the way of the dinosaurs thanks to streaming boxes like the Apple TV, video game consoles, and smart TVs. Samuel Axon, Ars Technica, "What Apple might announce at its October 30 “special event” in Brooklyn," 26 Oct. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'dinosaur.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of dinosaur

1841, in the meaning defined at sense 1

History and Etymology for dinosaur

New Latin Dinosaurus, genus name, from Greek deinos terrifying + sauros lizard — more at dire

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Statistics for dinosaur

Last Updated

5 Dec 2018

Look-up Popularity

Time Traveler for dinosaur

The first known use of dinosaur was in 1841

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More Definitions for dinosaur



English Language Learners Definition of dinosaur

: one of many reptiles that lived on Earth millions of years ago

: someone or something that is no longer useful or current : an obsolete or out-of-date person or thing


di·​no·​saur | \ˈdī-nə-ˌsȯr \

Kids Definition of dinosaur

: any of a group of extinct often very large mostly land-dwelling reptiles that lived millions of years ago

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Comments on dinosaur

What made you want to look up dinosaur? Please tell us where you read or heard it (including the quote, if possible).


the figure or shape of a crescent moon

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