laugh your head off

Từ điển Oxford Advanced Learner 8th

▪ I. laugh your ˈhead off idiom
to laugh very loudly and for a long time
Main entry: ↑laugh_idiom
 
▪ II. laugh, scream, etc. your ˈhead off idiom
(informal)to laugh, etc. a lot and very loudly
Main entry: ↑head_idiom