Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

Mesosaurus

noun
Meso·​sau·​rus | \-rəs\

Definition of Mesosaurus 

: a genus of small aquatic presumably fish-eating Permian reptiles of South America and southern Africa

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

History and Etymology for Mesosaurus

New Latin, from mes- + -saurus

Keep scrolling for more

Learn More about Mesosaurus

Share Mesosaurus

Statistics for Mesosaurus

Look-up Popularity

Comments on Mesosaurus

What made you want to look up Mesosaurus? Please tell us where you read or heard it (including the quote, if possible).

Show Comments  Hide Comments 

WORD OF THE DAY

zibeline

a soft lustrous wool fabric with mohair

Get Word of the Day daily email!

Test Your Vocabulary

Late Autumn 2018 Words of the Day Quiz

  • frosted-autumn-leaves
  • Which is a synonym of yahoo?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

Ask the Editors

Word Games