What is the meaning of idiom zip your lips?

The idiom "zip your lips" means to stop talking, to keep quiet, or to be silent. It's a more informal and often humorous way of saying "be quiet."

Here are some examples of how it's used:

* "I know you're excited, but zip your lips! We don't want to spoil the surprise."

* "That's a secret, so zip your lips about it."

* "He just couldn't zip his lips about what happened at the party."

The imagery of zipping your lips like a zipper evokes the idea of a sudden and complete closure of the mouth, preventing any further words from escaping.