mum

¹ American  

[muhm] / mʌm /

adjective

1. silent; not saying a word.

   to keep mum.

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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.

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mum ³ American  

[muhm] / mʌm /

noun

1. chrysanthemum.

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mum ⁴ American  

[muhm] / mʌm /

noun

Chiefly British.

1. mom.

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mum ⁵ American  

[muhm] / mʌm /

noun

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

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mum ⁶ American  

[muhm] / mʌm /

noun

Chiefly British.

1. madam.

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mum ¹ British  

/ mʌm /

adjective

1. keeping information to oneself; silent

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noun

1. silence or secrecy is to be observed

mum ² British  

/ mʌm /

noun

1. an informal word for mother 1

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mum ³ British  

/ mʌm /

verb

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

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mum ⁴ British  

/ mʌm /

noun

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

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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.

Example Sentences

When bad things happened in China, the news apps were often mum.

From The Wall Street Journal • May 5, 2026

When Millie Bright announced her retirement on Wednesday, her mum gave her a letter.

From BBC • Apr. 30, 2026

The mum said she then wrote a petition asking Shein to remove "inappropriate children's clothing" from its website.

From BBC • Apr. 30, 2026

She said she felt "sad" for her mum friends in Wales.

From BBC • Apr. 27, 2026

Lily and her mum came to visit on the weekend, too, but he made sure he spent the whole time they were there reading magazines in the gift shop.

From "A Monster Calls" by Patrick Ness

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