- 1a place for watching from, especially for danger or an enemy coming towards you a lookout point/tower
- 2a person who has the responsibility of watching for something, especially danger, etc. One of the men stood at the door to act as a lookout. Idioms (British English, informal) used to say that you do not think somebody’s actions are sensible, but that it is their own problem or responsibility. If he wants to waste his money, that's his lookout.
(informal) to watch carefully for somebody/something in order to avoid danger, etc. or in order to find something you want The public should be on the lookout for symptoms of the disease. The guards have to keep a sharp lookout for anything suspicious.