To save this word, you'll need to log in.
Definition of legion
(Entry 1 of 2)
1 : the principal unit of the Roman army comprising 3000 to 6000 foot soldiers with cavalry
Caesar and his legions defeated the Gauls.
3 : a very large number : multitude won him … a legion of devoted followers— Irving Kolodin
4 : a national association of ex-servicemen
the American Legion
legion
adjectiveKeep scrolling for more
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Test Your Vocabulary
Semantic Drift Quiz
- Which of the following was once a synonym for fun?

Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Share legion
Time Traveler for legion
The first known use of legion was in the 13th century
See more words from the same century