Definition of "dinosaur" in English

noun

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.

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.

4. (figuratively, colloquial) Something or someone that is very old or old-fashioned, or is not willing to change and adapt.

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