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Synonyms

mum

1 American  
[muhm] / mʌm /

adjective

  1. silent; not saying a word.

    to keep mum.


interjection

  1. (used to demand immediate silence.)

idioms

  1. mum's the word, do not reveal what you know (about something); keep silent.

    Mum's the word, or the surprise party won't be a surprise.

mum 2 American  
[muhm] / mʌm /
Or mumm

verb (used without object)

mummed, mumming
  1. to say “mum”; call for silence.

  2. to act as a mummer.


mum 3 American  
[muhm] / mʌm /
mum 4 American  
[muhm] / mʌm /

noun

Chiefly British.
  1. mom.


mum 5 American  
[muhm] / mʌm /

noun

  1. a strong beer or ale, first made in Brunswick, Germany.


mum 6 American  
[muhm] / mʌm /

noun

Chiefly British.
  1. madam.


mum 1 British  
/ mʌm /

adjective

  1. keeping information to oneself; silent

"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

noun

  1. silence or secrecy is to be observed

"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
mum 2 British  
/ mʌm /

noun

  1. an informal word for mother 1

"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

mum 3 British  
/ mʌm /

verb

  1. (intr) to act in a mummer's play

"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

mum 4 British  
/ mʌm /

noun

  1. obsolete a type of beer made from cereals, beans, etc

"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

Usage

What does mum mean? Mum is an adjective that means keeping quiet. It can also be used by itself to mean Be quiet!This sense of mum is especially used in the expressions keep mum and mum’s the word. In the U. K. and other places, mum is used as a word for mom or madam. It’s also commonly used as a short way of saying chrysanthemum, a type of flower. Example: Mum’s keeping mum—I can’t get a word out of her!

Etymology

Origin of mum1

First recorded in 1350–1400; Middle English momme; imitative

Origin of mum2

First recorded in 1350–1400; Middle English mommen, verb use of mum 1; compare Middle Dutch mommen ”to act the mummer's part”

Origin of mum3

First recorded in 1890–95; shortened form

Origin of mum4

First recorded in 1815–25; nursery word; see mom

Origin of mum5

First recorded in 1630–40; from German Mumme, said to have been named after Christian Mumme, the brewer who made it

Origin of mum6

Variant of ma'am

Explanation

Someone who's mum has nothing to say, especially on a particular subject. If you agree to keep someone's secret, you could tell them, "Mum's the word!" A shy child who's new at school might stay mum all day, and even your most talkative friend might remain mum on controversial topics like religion and politics. In many parts of the world, mum is also a nickname for your mother — and it's also a nickname for the flower called a chrysanthemum. The "quiet" meaning of mum comes from Old English, inspired by the "mmm" sound you make when your lips are closed.

Keep Reading on Vocabulary.com

Vocabulary lists containing mum

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.

Ed Cullen, from Taunton in Somerset, said when his mum died, she arranged an unattended cremation because she thought it was cheaper - leaving him and his family without the chance to say goodbye.

From BBC • May 15, 2026

By then, Celeste's contact with Valdo became less frequent and when they did speak, Valdo told his mum he was taking his medication and was "fine", she said.

From BBC • May 14, 2026

"It's a really good t-shirt - 'Look mum, no points'."

From BBC • May 14, 2026

Revisiting, Alex wanted to find out "what my mum was looking for and why such drastic measures were necessary".

From BBC • May 13, 2026

“If it was my mum, I’d want to know what happened.”

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

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