brontosaur

/ˈbrɑntəˌsɔr/
noun
  1. A very large, long-necked dinosaur that lived during the Jurassic period; another name for brontosaurus.
    • The brontosaur is one of the most famous dinosaurs because of its huge size.
    • Scientists once thought the brontosaur was a different species from the apatosaurus.
    • Kids often draw brontosaurs with their long necks reaching up to treetops.