(informal)remain silent, especially so as not to reveal a secret(非正式)（尤指為保密）保持沉默，守口如瓶
mum's the word
Say nothing of the secret you know保密：保守你知道的秘密
Your mum is your mother.
He misses his mum...他想念他的媽媽。Mum and Dad are coming for lunch...爸爸和媽媽要來吃午飯。
If you keep mum or stay mum about something, you do not tell anyone about it.
He is keeping mum about his feelings on the matter.他閉口不談他對此事的個人感受。
There was always a honeymoon period when Mum started a new job.媽媽每開始一份新工作總會有一陣兒新鮮勁。The cat acted as a surrogate mum to the chicks.這只貓當起了小雞的媽媽來。Your mum will go spare if you don’t go to school!要是你不上學,你媽媽會氣壞的!
I just kept mum when she asked me where Ben was. She’d be furious if she knew.她問我本在哪里,我沒有告訴她。如果她知道了,一定非常生氣。
I just kept mum when she asked me where Ben was. She’d be furious if she knew.她問我本在哪里，我沒有告訴她。如果她知道了，一定非常生氣。Please will everyone keep mum about Saturday. We want to give them a real surprise.請大家對周六的事情保密，我們想給他們一個驚喜。
‘Nobody must mention this project outside the office. I hope that’s clear.’ ‘We understand, John. Mum’s the word!’“請大家千萬不要在辦公室以外的地方談論這個項目，我希望每個人都明白這一點?！薄凹s翰，放心吧，我們都理解，守口如瓶！”
1. of China
2. informal terms for a mother
"mum's the word"
1. failing to speak or communicate etc when expected to;