involvement vs liaison

involvement and liaison both are nouns.

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

As nouns, involvement and liaison are synonyms defined as:

involvement and liaison: a usually secretive or illicit sexual relationship

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

involvement (noun)	liaison (noun)
the act of sharing in the activities of a group	a channel for communication between groups
a sense of concern with and curiosity about someone or something	a usually secretive or illicit sexual relationship
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.)