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em

1 American  
[em] / ɛm /

noun

plural

ems

  1. the letter M, m.

  2. Also called mut, mutton.  Printing.

    1. the square of any size of type used as the unit of measurement for matter printed in that type size.

    2. (originally) the portion of a line of type occupied by the letter M in type of the same size.

  3. em pica.

adjective

  1. Printing. having the area of an em quad or the length of an em dash.

'em 2 American  
[uhm] / əm /

pronoun

Informal.

  1. them.

    Put 'em down there.
Em 3 American  
Symbol, Physical Chemistry.

  1. emanation.

EM 4 American  

abbreviation

  1. electromagnetic.

  2. electromotive.

  3. electronic mail.

  4. electron microscope; electron microscopy.

  5. end matched.

  6. Engineer of Mines.

  7. enlisted man; enlisted men.

em- 5 American  

  1. variant of en- before b, p, and sometimes m:

    embalm.
em- 6 American  

  1. variant of en- before b, m, p, ph:

    embolism, emphasis.
E.M. 7 American  

abbreviation

  1. Earl Marshal.

  2. Engineer of Mines.

em 1 British  
/ ɛm /

noun

  1. Also called: mutton.   mut.  the square of a body of any size of type, used as a unit of measurement

  2. Also called: pica em.   pica.  a unit of measurement used in printing, equal to one sixth of an inch

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
'em 2 British  
/ əm /

pronoun

  1. an informal variant of them

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
em- 3 British  

prefix

  1. before b, m, and p, a variant of en- 1 en- 2

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of em1

First recorded in 1860–65

Origin of 'em2

First recorded in 1350–1400; Middle English hem, Old English heom, dative and accusative plural of he 1

Vocabulary lists containing em

Scrabble: Two-Letter Words

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Because more than any other punctuation mark, the em dash is deeply human.

From The Wall Street Journal • Nov. 20, 2025

“I told em, ‘yeah I got couple of those.’

From Los Angeles Times • Sep. 6, 2025

“Some of em last for a long time if we’re lucky, but most of them are fleeting,” he wrote.

From Los Angeles Times • Sep. 2, 2025

Along with the now-infamous em dash, many are renouncing words for which ChatGPT is known to have a mysterious penchant, such as delve, nestled, boast, and meticulous.

From Slate • Aug. 20, 2025

Them prisoners don’t get but one out a ten things sent to em cause the lady guards take it for theyselves.

From "The Help" by Kathryn Stockett

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.