Synonyms for Lookout (same or very similar meaning)
WordNet sense 1 (a person employed to watch for something to happen):
picket, scout, sentinel, sentry, spotter, watch, lookout man
WordNet sense 2 (an elevated post affording a wide view):
observation post
WordNet sense 3 (a structure commanding a wide view of its surroundings):
observatory, lookout station, observation tower
WordNet sense 4 (the act of looking out):
outlook
From the ODE community, based on WordNet
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