SINCE 1828
em
noun
\ ˈem
\
\
Definition of em
(Entry 1 of 3)
1
: the letter m
2
: the width of a piece of type about as wide as it is tall used as a unit of measure of typeset matter
EM
abbreviationDefinition of EM (Entry 2 of 3)
1
electromagnetic
2
electron microscope; electron microscopy
3
end matched
4
engineer of mines
5
enlisted man
em-
prefixDefinition of em- (Entry 3 of 3)
— see en-
Keep scrolling for more
Keep scrolling for more
Comments on em
What made you want to look up em? Please tell us where you read or heard it (including the quote, if possible).
Test Your Vocabulary
Original Meanings Quiz
-
- Which of the following is the earliest known sense of the word awe?
Test your visual vocabulary with our 10-question challenge!
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
-
Original Meanings Quiz
A quiz for the pedantic and those annoyed by them!
Take the quiz -
A Green Quiz
How many questions can you answer about the word "green"?
Take the quiz -
Name That Thing
Test your visual vocabulary with our 10-question challenge!
Take the quiz -
Syn City
Build a city of skyscrapers—one synonym at a time.
Play the game
Share em
Resources for em