scout
noun
1 scouts reported that the enemy were massing at two points ahead:
lookout, lookout man/woman, outrider, advance guard, vanguard, spy;
French avant-courier.
verb
2 a night patrol was sent to scout out the area:
reconnoiter, explore, take a look at, make a reconnaissance of, inspect, investigate, spy out, survey, make a survey of;
examine, scan, study, observe;
see how the land lies, find out the lie of the land;
informal recce, make a recce of, check out, case, case the joint;
British, informal take a shufti round, suss out;
North American, informal recon.