collaborator vs collaborationist

collaborator and collaborationist both are nouns.

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

As nouns, collaborator and collaborationist are synonyms defined as:

collaborator and collaborationist: someone who collaborates with an enemy occupying force

Other synonyms of collaborator include quisling.

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