dinosaur

1. (sciences) Any of the animals belonging to the clade Dinosauria, especially those that existed during the Triassic, Jurassic and Cretaceous periods and are now extinct.

2. (colloquial) Any member of the clade Dinosauria other than birds.Synonyms: non-avian dinosaurcolloquial

3. (proscribed) 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.Examples: ""Not a bird, my dear Roxton - not a bird." "A beast?" "No; a reptile - a dinosaur.""; "‘Dinosaur!’ Denham exploded. ‘By the Power! A dinosaur!’"proscribed

4. (figuratively, colloquial) Something or someone that is very old or old-fashioned, or is not willing to change and adapt.Examples: "[The OS/360 linkage editor] is the culmination of years of development of static overlay technique. Yet it is also the last and finest of the dinosaurs, for it belongs to a system in which multiprogramming is the normal mode and dynamic core allocation the basic assumption."; "The sign in the window said for sale or trade on the last remaining dinosaur Detroit made."Synonyms: fossil, old fartcolloquialfiguratively

5. (figuratively, colloquial) Anything no longer in common use or practice.colloquialfiguratively