lookout

Từ điển Oxford Advanced Learner 8th

look·out [lookout lookouts] BrE [ˈlʊkaʊt] NAmE [ˈlʊkaʊt] noun
1. a place for watching from, especially for danger or an enemy coming towards you
•a lookout point/tower
2. a person who has the responsibility of watching for sth, especially danger, etc
•One of the men stood at the door to act as a lookout.
Idioms: ↑keep a lookout ▪ ↑on the lookout ▪ ↑somebody's lookout

Example Bank:
•The guards have to keep a sharp lookout for anything suspicious.