lookout

noun

1.
a person employed to keep watch for some anticipated event
picket scout sentinel sentry spotter watch
Derived from:
look out
2.
an elevated post affording a wide view
observation post
Derived from:
look out
3.
a structure commanding a wide view of its surroundings
watchhouse lookout station observation tower observatory
Derived from:
look out
4.
the act of looking out
outlook
Derived from:
look out