Urban Dictionary: mum's the word

1.	mum's the word
	means to keep this a secret; don't tell anybody I don't want anybody to know about this affair until next week, so mum's the word! buy mum's the word mugs & shirts keep mum about it keep secret keep in dark to keep mum bosom. by Venera Dec 22, 2005 add a video
2.	mum's the word
	keep quiet about it (possibly from the sound one makes when trying to speak with closed lips, Attributed to William Shakespeare) Remember, until further notice, mum's the word. buy mum's the word mugs & shirts button up idioms mum's-the-word mum'stheword my lips are sealed by The Return of Light Joker Jan 8, 2010 add a video