discoverer vs spotter

discoverer and spotter both are nouns.

Word	Noun	Adjective	Verb	Adverb
discoverer	Yes	No	No	No
spotter	Yes	No	No	No

As nouns, discoverer and spotter are synonyms defined as:

Other synonyms of discoverer include finder.

discoverer (noun)	spotter (noun)
someone who is the first to observe something	someone who is the first to observe something
someone who is the first to think of or make 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