dinosaur

noun

1. 1

   In scientific usage, 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. 2

   In non-scientific usage, any non-avian dinosaur.

3. 3

   Any extinct reptile, not necessarily belonging to Dinosauria, that existed between about 230 million and 65 million years ago.

4. 4

   A person or organisation that is very old, has very old-fashioned views, or is not willing to change and adapt.

5. 5

   Anything no longer in common use or practice.