mum’s the word
mum's the word
- keep quiet and say nothing
- do not say anything or give away a secret
- keep silent and not reveal something
- We are throwing a party for our friend Jeremy, but its a surprise, so don't tell him anything about it. Mum's the word.
- I'll tell you about our secret hiding place, but mum's the word; don't tell anyone about it.
- Mum's the word about tonight's plan. We don't want all and sundry to gatecrash into our private gathering.
- The information I am going to reveal to you is highly confidential, so mum's the word.
- I know where he has gone, but I am not revealing it to anyone against his wishes, so mum's the word.
- I'll let you on our little secret, but mum's the word: if anyone else gets to know of it, we'll be in big trouble.
- I've heard the news, but mum's the word till we get confirmation.
The phrase originated around the 17th century. An earlier version of the phrase was "mum is counsel", and was used in the 16th century. The earliest print reference of this exact phrase can be found in "A Walk Around London and Westminster - The Works of Mr. Thomas Brown" from 1720.