Definiția și Sensul lui "mum is the word"

What is the origin of the idiom "mum is the word" and when to use it?

The idiom "mum is the word" originated from the Middle English word "mum," which meant to keep silent or be quiet. The phrase signifies the act of maintaining secrecy or confidentiality, often in situations where it is important not to reveal sensitive information or to keep a secret. The idiom suggests that one should remain silent and refrain from speaking about a particular matter. It implies the need for discretion and emphasizes the importance of keeping one's lips sealed.