Definition of dinosaur in English:


See synonyms for dinosaur on

Translate dinosaur into Spanish


  • 1A fossil reptile of the Mesozoic era, in many species reaching an enormous size.

    The dinosaurs are placed, according to their hip structure, in two distantly related orders (see
    ). Some of them may have been warm-blooded, and their closest living relatives are the birds. Dinosaurs were all extinct by the end of the Cretaceous period (65 million years ago), a popular theory being that the extinctions were the result of the impact of a large meteorite

    ‘These great birds were the last successors of the mighty theropod dinosaurs of the Mesozoic.’
    • ‘We are so used to the enormous size of dinosaurs that we almost forget to think about how they grew to be so large.’
    • ‘They do still have two skeletons of Tarbosaurus, a theropod dinosaur related to Tyrannosaurus rex.’
    • ‘The layer was generally at the place in the fossil record where the dinosaurs disappeared.’
    • ‘The dinosaurs of the Mesozoic era in a sense presaged the birds and mammals of the Cenozoic era.’
    • ‘More distantly related to true dinosaurs were the marine plesiosaurs and ichthyosaurs.’
    • ‘Birds arose from theropod dinosaurs at some point in the Jurassic, according to present knowledge.’
    • ‘There were many kinds of ornithischian dinosaurs, dating back to the early Jurassic.’
    • ‘The ornithodires went on to produce pterosaurs and dinosaurs, including the birds.’
    • ‘At the foot of the mountain, colourful fossils of shells and dinosaurs add a mysterious flavour to the place.’
    • ‘His work provided strong, compelling support for the theory that birds are theropod dinosaurs.’
    • ‘The ornithopod dinosaurs that left these tracks may have been quadrupedal, walking on all fours.’
    • ‘Ichthyosaurs were not dinosaurs, but represent a separate group of marine vertebrates.’
    • ‘These were the fragmentary remains of an armored dinosaur, an ankylosaur.’
    • ‘The size of dinosaurs, whales, and elephants should serve as an example.’
    • ‘There is the added question of how the dinosaurs are to be fossilised in a desert.’
    • ‘It was a fairly large dinosaur, the same size as the future Tyrannosaurus Rex.’
    • ‘At the time, paleontologists were stuck in a reptilian perspective on dinosaurs.’
    • ‘He was also able to travel to Bloemfontein to compare the fossils with those of an early dinosaur in the National Museum.’
    • ‘If it is alive then it probably is not a dinosaur, since dinosaurs are extinct.’
    fogey, old fogey, conservative, traditionalist, conventionalist, diehard, conformist, bourgeois, museum piece, fossil, dinosaur, troglodyte
  • 2A person or thing that is outdated or has become obsolete because of failure to adapt to changing circumstances.

    ‘I still get invites but I feel like a dinosaur and a bit of a has-been now.’
    • ‘He is like a Tyrannosaurus Rex, leading a herd of corporate dinosaurs over the cliff and bellowing as he goes.’
    • ‘She said: "I suppose at 30 I'm considered a bit of a dinosaur in the industry."’
    • ‘This ballet is a bit of a dinosaur.’



/ˈdīnəˌsôr/ /ˈdaɪnəˌsɔr/


Mid 19th century from modern Latin dinosaurus, from Greek deinos ‘terrible’ + sauros ‘lizard’.