adjective
Definition: Not speaking or making noise; quiet.
Example: The room was mum as everyone listened to the speaker.
interjection
Definition: A word used to tell someone to be quiet or stop talking.
Example: "Mum! I can't hear the movie!"
intransitive verb
Definition: To perform or act in a silent or mimed way, often as part of a celebration or festival.
Example: The children decided to mum during the school play, using gestures instead of words.
noun
Definition: A word used mainly in British English to refer to a mother.
Example: My mum makes the best cookies in the world.