From WordNet (r) 3.0 (2006):
lookout
n 1: a person employed to keep watch for some anticipated event
[syn: lookout, lookout man, sentinel, sentry,
watch, spotter, scout, picket]
2: an elevated post affording a wide view [syn: lookout,
observation post]
3: a structure commanding a wide view of its surroundings [syn:
lookout, observation tower, lookout station,
observatory]
4: the act of looking out [syn: lookout, outlook]