involvement

(noun) the act of sharing in the activities of a group. Synonyms: engagement, participation, involution. Example: "The teacher tried to increase his students' engagement in class activities."

(noun) a connection of inclusion or containment. Examples: "He escaped involvement in the accident." "There was additional involvement of the liver and spleen."

(noun) a sense of concern with and curiosity about someone or something. Synonyms: interest. Example: "An interest in music."

(noun) a usually secretive or illicit sexual relationship. Synonyms: affair, affaire, intimacy, liaison, amour.

(noun) the condition of sharing in common with others (as fellows or partners etc.). Synonyms: participation.