[ em ]

noun,plural ems.
  1. the letter M, m.

  2. Also called mut, mutton. Printing.

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

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

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

Origin of em

First recorded in 1860–65

Other definitions for 'em (2 of 7)

[ uhm ]

  1. them: Put 'em down there.

Origin of 'em

First recorded in 1350–1400; Middle English hem, Old English heom, dative and accusative plural of he1

Other definitions for Em (3 of 7)


Symbol, Physical Chemistry.

Other definitions for EM (4 of 7)


  1. electronic mail.

  2. electron microscope; electron microscopy.

  3. end matched.

  4. Engineer of Mines.

  5. enlisted man; enlisted men.

Other definitions for em- (5 of 7)


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

Other definitions for em- (6 of 7)


  1. variant of en-2 before b, m, p, ph:embolism, emphasis.

Other definitions for E.M. (7 of 7)


  1. Earl Marshal.

  2. Engineer of Mines.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use em in a sentence

  • All storm signals set, and E.M.'s secretary telephoning that the Great Man wants to see you at once.

    The Clarion | Samuel Hopkins Adams
  • How many readers care whether E.M. Pierce's daughter ran over a woman or not?

    The Clarion | Samuel Hopkins Adams

British Dictionary definitions for em (1 of 3)


/ (ɛm) /

  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

Origin of em

C19: from the name of the letter M

British Dictionary definitions for 'em (2 of 3)


/ (əm) /

  1. an informal variant of them

British Dictionary definitions for em- (3 of 3)


  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