1a place from which to keep watch or view the landscape: [as modifier]:a fortified lookout towera lookout point with breathtaking views
a person stationed to keep watch for danger or trouble:they acted as lookouts at the post office
archaic a view over a landscape.
2 [in singular, with adjective] informal, chiefly British used to indicate whether a likely outcome is good or bad:‘What if he gets fits?’ ‘It’s a bad lookout in that case.’
be one's (own) lookout
British informal be a person’s own responsibility or problem:if you can’t take an interest in local affairs, that’s your lookout
be on the lookout (or keep a lookout) for
be alert to (danger or trouble):he told them to be on the lookout for dangerous gas
keep searching for (something that is wanted):we kept a sharp lookout for animals and saw several waterbuck