- mum
- adj1. silent, speechless, mute, dumb, noiseless, soundless, aphonic; voiceless, nonvocal, wordless, pantomimic; reticent, taciturn, quiet, uncommunicative, reserved; tight-lipped, closed-mouthed, tonguetied, buttoned up; evasive, secretive, noncommital.2. mum's the wordkeep silent, don't tell anyone, cross your heart and hope to die, keep secret, keep to oneself, keep under one's hat, play dumb.
A Note on the Style of the synonym finder. 2014.