eavesdropper vs snooper

eavesdropper and snooper both are nouns.

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

As nouns, snooper is a hypernym of eavesdropper; that is, snooper is a word with a broader meaning than eavesdropper:

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

Other hypernyms of eavesdropper include attender, auditor, hearer, listener, snoop.

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