Definitions
1.nounIn 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.nounIn non-scientific usage, any non-avian dinosaur.
3.nounAny extinct reptile, not necessarily belonging to Dinosauria, that existed between about 230 million and 65 million years ago.
4.nounA person or organisation that is very old, has very old-fashioned views, or is not willing to change and adapt.
5.nounAnything no longer in common use or practice.