Mum's the word.
[Idiom] MUM'S THE WORD. - The Art of Keeping Secrets in Conversations
keep this a secret
The expression 'Mum's the word' is an interesting way to request or confirm secrecy. It finds its roots in the Middle English word 'mum,' meaning 'silent' or 'not speaking.' Thus, when someone says 'Mum's the word,' they are essentially saying 'remain silent on this matter.' This idiom is perfect for moments that require confidentiality, whether sharing personal news, planning a surprise, or discussing sensitive information. It invokes an understanding that the listener must not only avoid disclosing the information but also not acknowledge it. Incorporating this phrase can add an air of mystery and importance and reinforce the trust necessary between parties when handling privileged information.
Example Sentences
Don't tell anyone about the surprise party, mum's the word.
Keep the surprise party a secret.
Even with everyone asking, he knew mum's the word about the company's plans.
Despite being asked, he kept the company's plans confidential.
She gave him a stern look and reminded him, mum's the word, it's a secret.
She reminded him to keep the secret and not tell anyone.
