collaborator vs cooperator

collaborator and cooperator both are nouns.

Word	Noun	Adjective	Verb	Adverb
collaborator	Yes	No	No	No
cooperator	Yes	No	No	No

As nouns, collaborator and cooperator are synonyms defined as:

collaborator and cooperator: an associate in an activity or endeavor or sphere of common interest

Other synonyms of collaborator include pardner, partner.

collaborator (noun)	cooperator (noun)
an associate in an activity or endeavor or sphere of common interest	an associate in an activity or endeavor or sphere of common interest
someone who collaborates with an enemy occupying force
someone who assists in a plot