dinosaur

noun5

1. •
   Those animals of the clade Dinosauria that existed during the Triassic, Jurassic and Cretaceous periods and are now extinct.

   • Despite what some cartoons portray, no humans were around when dinosaurs roamed the Earth.
2. •
   Any of the animals belonging to the clade Dinosauria, including its sole surviving lineage: Neornithes.

   • Many people love their backyard birds, but some of us may not realize that those feathery friends are also literally dinosaurs, in a biologically accurate sense of that word.
3. •
   (informal, nonstandard) Any extinct reptile, not necessarily belonging to Dinosauria, that existed between about 230 million and 65 million years ago, as well as the stem-mammal Dimetrodon.

   • Pterosaurs, plesiosaurs, icthyosaurs — I don't know, they're all dinosaurs to me!
4. •
   (informal, figurative) Someone or something that is very old or old-fashioned, especially someone who is not willing to change and adapt.

   • She may be a tough old bird, but it's a mistake to write her off as a dinosaur; you do so at your own risk.
5. •
   (informal, figurative) Anything no longer in common use or practice.

   • I couldn't believe it when I saw the equipment that they were still using. Those machines were all dinosaurs, but they were busily cranking out production.