Definition of hadrosaur
: any of a genus (Hadrosaurus) or family (Hadrosauridae) of mainly bipedal dinosaurs of the Late Cretaceous that have the forward part of the jaws toothless and flattened into a beak-like snout and the back part of the jaws filled with rows of numerous small, grinding teeth and that often have a solid or hollow bony crest on the skull : duck-billed dinosaur … the hadrosaurs evolved into some 21 different species during their 20 million-year stint on earth …— Virginia Morell
Keep scrolling for more
Test Your Vocabulary
Slippery Words Quiz—Changing with the Times
- What is an earlier meaning of nice?

Test your visual vocabulary with our 10-question challenge!
TAKE THE QUIZ
Spell words. Make bears.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Share hadrosaur
Time Traveler for hadrosaur
The first known use of hadrosaur was in 1877
See more words from the same year