Dinosaur means an extinct reptile that lived millions of years ago, and it can also mean something old-fashioned or no longer useful.

Simple meaning

  • Literal meaning: a prehistoric reptile from the age of dinosaurs.
  • Figurative meaning: a person, thing, or idea that is outdated and slow to change.

Example

  • “T. rex was a dinosaur.”
  • “That computer is a dinosaur.”

Word note

The word is commonly explained as meaning “terrible lizard,” though modern sources note that the original Greek roots are often understood more like “fearfully great lizard” or “powerful lizard.”

If you want, I can also explain the word’s origin in one sentence.