Mum’s the word this Wordy Wednesday, but don’t go telling anyone that you know what this secretive phrase means! And, no, it has nothing to do with your mother. Rather, the word “mum” derives from the “mmm” sound your mouth makes when it’s shut and, therefore, better for keeping secrets. It could also come from the Old French verb momer, meaning to “wear a mask.” If you are familiar with the word “mime,” referring to a silent performance, than you know how to be “mum.” Simply close your lips and keep quiet.
All we know for sure is that Shakespeare first used the phrase in his play, Henry VI, Part 2, in which characters are constantly plotting and keeping secrets from each other:
Seal up your lips, and give no words but mum:
The business asketh silent secrecy.
Henry VI Part 2
The next time you have sensitive information to withhold, mum’s the word.