dinosaur

noun
di·​no·​saur | \ ˈdī-nə-ˌsȯr How to pronounce dinosaur (audio) \

Definition of dinosaur

1 : any of a group (Dinosauria) of extinct, often very large, carnivorous or herbivorous archosaurian reptiles that have the hind limbs extending directly beneath the body and include chiefly terrestrial, bipedal or quadrupedal ornithischians (such as ankylosaurs and stegosaurs) and saurischians (such as sauropods and theropods) which flourished during the Mesozoic era from the late Triassic period to the end of the Cretaceous period The dinosaurs, which once dominated the earth, disappeared very swiftly, leaving room for tiny shrewlike creatures to crawl out of shelter and start on the road to mammalian domination of the planet.— D. E. Thomsen Most scientists now concur that at least one great extraterrestrial object struck the planet around the time the dinosaurs died out.— Rick Gore also : any of a broader group that also includes all living and extinct birds The overwhelming majority of scientists are now convinced that birds are theropod dinosaurs— James O'Donoghue

Note: Dinosaurs have traditionally been considered a separate group from birds, which evolved from dinosaurs, but modern paleontologists now view birds as survivors of a theropod lineage of dinosaurs. In this classification, all dinosaurs except birds became extinct at the end of the Cretaceous period approximately 65 million years ago, with all dinosaurs that are not birds referred to as dinosaurs or non-avian dinosaurs and birds typically referred to as avian dinosaurs.

2 : any of various large extinct reptiles (such as an ichthyosaur or mosasaur) 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3 : one that is impractically large, out-of-date, or obsolete The factory is now a rusting dinosaur.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 How to pronounce dinosaurian (audio) \ adjective
dinosauric \ ˌdī-​nə-​ˈsȯr-​ik How to pronounce dinosauric (audio) \ adjective

Synonyms for dinosaur

Synonyms

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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 Part of the problem is that many of the largest dinosaur skeletons are incomplete. Riley Black, Scientific American, "Why the World’s Biggest Dinosaurs Keep Getting Cut Down to Size," 13 Oct. 2020 The moving company knows a thing or two about cardboard boxes and has created a series of How-To-Videos to help make a silly T-Rex dinosaur, an adorable flower pot and even a mermaid costume for your favorite pup. Kirby Adams, The Courier-Journal, "From 'spooktacular' trees to ghoulish treats, how to do Halloween in (safe!) style in 2020," 12 Oct. 2020 Magic of Lights follows the summer success of Jurassic Quest, a drive-through dinosaur exhibition on the sprawling parking lot of a venue that normally would have been teeming with concerts. Brian Mccollum, Detroit Free Press, "Magic of Lights drive-through display to hit DTE amphitheater grounds for holiday season," 9 Oct. 2020 Show up to your next Halloween party in prehistoric style with these inflatable dinosaur costumes. Sian Babish, chicagotribune.com, "Best friend Halloween costumes of 2020," 8 Oct. 2020 This dinosaur costume has a long, scaly tail that can fit on both cats and dogs. Erika Hardison, USA TODAY, "15 amazing pet Halloween costumes you need to buy," 8 Oct. 2020 Scientists also theorize that the dinosaur weighed nearly 8 tons, the Times added. Chris Ciaccia, Fox News, "Enormous T. Rex skeleton sold at auction for $32M: 'One of the best specimens ever discovered'," 7 Oct. 2020 And as if to cap off the absurdity, Monday also brought news that Arsenal had furloughed an 8-foot dinosaur in a baseball cap. Joshua Robinson, WSJ, "The Week English Soccer Lost the Plot," 7 Oct. 2020 That effort included featuring the dinosaur fossil among Impressionist and Modern paintings. Zachary Small, New York Times, "T. Rex Skeleton Brings $31.8 Million at Christie’s Auction," 6 Oct. 2020

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

borrowed from presumed New Latin *dinosaurus, the base of Dinosauria, former reptile taxon, from Greek deinós "inspiring dread or awe" + -o- -o- + New Latin Sauria, former reptile suborder, from Greek saúros "lizard" + New Latin -ia -ia entry 2 — more at deinonychus, -saurus

Note: The taxonomic name Dinosauria as well as the vernacular form dinosaur were both introduced by the British biologist and paleontologist Richard Owen (1804-92) in "Report on British Fossil Reptiles. Part II," Report of the Eleventh Meeting of the British Association for the Advancement of Science ("Held at Plymouth in July 1841") (London: J. Murray, 1842), p. 103: "The combination of such characters, some, as the sacral ones [i.e., the sacral vertebrae fused into a single structure], altogether peculiar among Reptiles, others borrowed, as it were, from groups now distinct from each other, and all manifested by creatures far surpassing in size the largest of existing reptiles, will, it is presumed, be deemed sufficient ground for establishing a distinct tribe or sub-order of Saurian Reptiles, for which I would propose the name of Dinosauria. [Footnote to the above] Gr. deinòs, fearfully great; saúros, a lizard." Although Owen's "Report on British Fossil Reptiles" purports to be the record of an oral presentation given at Plymouth in July, 1841, the detailed contemporary accounts of Owen's lecture do not mention dinosaur or Dinosauria, and it is now clear that he only introduced the word with the extensively revised version of the report released in April, 1842. The background to Owen's report is analyzed by Hugh S. Torrens in "Politics and Paleontology: Richard Owen and the Invention of Dinosaurs," M. K. Brett-Surman, et al., editors, The Complete Dinosaur, 2nd edition (Indiana University Press, 2012), pp. 25-43. Offprints of Owen's article have the publication date 1841, but, as Torrens demonstrates (p. 34), this was an error (perhaps deliberately uncorrected by Owen). Owen's rendering of Greek deinós (a word with a wide semantic range) as "fearfully great" is at odds with the conventional notion that dinosaur means "terrible lizard" in Greek. Although "terrible" (i.e., terrifying) is a possible translation of deinós, it does not appear to be the meaning Owen intended.

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Time Traveler for dinosaur

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The first known use of dinosaur was in 1841

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Last Updated

17 Oct 2020

Cite this Entry

“Dinosaur.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dinosaur. Accessed 23 Oct. 2020.

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More Definitions for dinosaur

dinosaur

noun
How to pronounce dinosaur (audio)

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

dinosaur

noun
di·​no·​saur | \ ˈdī-nə-ˌsȯr How to pronounce dinosaur (audio) \

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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