Select the most appropriate meaning of the given Idiom: "Mum’s the word"

To keep quiet

The most appropriate meaning of the idiom "Mum's the word" is to keep quiet. This idiom comes from the literal meaning of the phrase, which is to tell someone to keep quiet, as if their mother would be angry if they spoke. In the same way, the idiom "Mum's the word" can be used to describe the act of telling someone to keep a secret, or to not talk about something.

The other meanings of the idiom "Mum's the word" are not as common. The meaning "to threat someone" is more likely to be expressed as simply "to threaten." The meaning "a magic word" is not associated with the idiom "Mum's the word" at all. The meaning "a very talkative person" is not associated with the idiom "Mum's the word" at all.