involvement vs affaire

involvement and affaire both are nouns.

Word	Noun	Adjective	Verb	Adverb
involvement	Yes	No	No	No
affaire	Yes	No	No	No

As nouns, involvement and affaire are synonyms defined as:

involvement and affaire: a usually secretive or illicit sexual relationship

Other synonyms of involvement include affair, amour, intimacy, liaison.

involvement (noun)	affaire (noun)
the act of sharing in the activities of a group	a usually secretive or illicit sexual relationship
a sense of concern with and curiosity about someone or something
a connection of inclusion or containment
a usually secretive or illicit sexual relationship
the condition of sharing in common with others (as fellows or partners etc.)