Zip it
Definitions
A command to stop talking or remain silent.
To cease speaking immediately.
Examples
The teacher told the noisy students to zip it so the exam could begin.
I was about to reveal the surprise, but my brother told me to zip it.
Synonyms
Keep quiet Hold your tongue Button your lip Silence please Shut your mouth
Antonyms
Speak up Start talking Voice your opinion Let it all out Break your silence