'mum's the word' definitions:
Definition of 'mum's the word'
- Mum \Mum\, a. [Of imitative origin. Cf. Mumble.]
Silent; not speaking; as, to keep mum. --Thackeray.
[1913 Webster]
- The citizens are mum, and speak not a word. --Shak.
[1913 Webster]
- mum's the word keep this a secret; don't tell anybody.
[PJC]
