belt up

Từ điển Oxford Advanced Learner 8th

ˌbelt ˈup derived
(BrE)
1. (NAmE ˌbuckle ˈup) (informal)to fasten your ↑seat belt (= a belt worn by a passenger in a vehicle)
2. (informal)used to tell sb rudely to be quiet
Syn: ↑shut up
•Just belt up, will you!
Main entry: ↑belt_derived