light on something

Từ điển Oxford Advanced Learner 8th

▪ I. be light on sth idiom
(BrE)to not have enough of sth
•We seem to be light on fuel.
Main entry: ↑light_idiom
 
▪ II. ˈlight on/upon sth derived
(literary)to see or find sth by accident
•His eye lit upon a small boat on the horizon.
Main entry: ↑light_derived