lookout man vs spotter

lookout man and spotter both are nouns.

Word	Noun	Adjective	Verb	Adverb
lookout man	Yes	No	No	No
spotter	Yes	No	No	No

As nouns, lookout man and spotter are synonyms defined as:

lookout man and spotter: a person employed to keep watch for some anticipated event

Other synonyms of lookout man include lookout, picket, scout, sentinel, sentry, watch.

lookout man (noun)	spotter (noun)
a person employed to keep watch for some anticipated event	someone who is the first to observe something
	a worker employed to apply spots (as markers or identifiers)
	a worker employed at a dry-cleaning establishment to remove spots
	a person employed to keep watch for some anticipated event