mum

In British English, your mum is your mother, so this is one of the first meanings many learners meet. It is a warm, everyday word, much less formal than "mother." A child might call out, "Mum, where are my shoes?" or say, "My mum makes the best soup." In American English, "mom" is more common, but the meaning is the same.

But "mum" also has an older meaning: quiet, silent, or not willing to speak. You still hear it in phrases like "mum's the word," which means "keep this a secret." You can also say someone is "mum about it" if they do not want to talk. That use is less common today, but it still appears in stories, conversations, and headlines.

"Mum" is a common everyday word with two main lives in English. In British English, it most often means "mother." It is the natural family word many children and adults use at home, in much the same way Americans say "mom." If someone says, "I'm going to visit my mum this weekend," they simply mean they are going to see their mother. The tone is personal, warm, and ordinary rather than formal.

There is also another meaning, older and more literary in feel. In this sense, "mum" means silent, quiet, or unwilling to speak. This is the meaning behind the well-known phrase "mum's the word," which tells someone to stay quiet and not share a secret. You might read, "He was mum on the subject," meaning he refused to discuss it, or "They stayed mum about the plan," meaning they kept it to themselves.

This second use is not about being unable to speak. It usually suggests a choice to stay quiet, often because of privacy, caution, or secrecy. A witness may stay mum during an investigation, or a friend may stay mum about a surprise party. You can also describe a person as "mum" if they seem unusually quiet or closed off, though that sounds a little old-fashioned now.

So the meaning depends on the context. In one sentence, "mum" is the person who raised you. In another, it means silence. Both uses are real, but the family meaning is far more common in modern daily speech, especially in British English.