snooper vs eavesdropper

snooper and eavesdropper both are nouns.

Word	Noun	Adjective	Verb	Adverb
snooper	Yes	No	No	No
eavesdropper	Yes	No	No	No

As nouns, eavesdropper is a hyponym of snooper; that is, eavesdropper is a word with a more specific, narrower meaning than snooper:

snooper: a spy who makes uninvited inquiries into the private affairs of others
eavesdropper: a secret listener to private conversations

snooper (noun)	eavesdropper (noun)
a spy who makes uninvited inquiries into the private affairs of others	a secret listener to private conversations