1 (often foll. by in) cause (a person or thing) to participate, or share the experience or effect (in a situation, activity, etc.).
2 imply, entail, make necessary.
3 (foll. by in) implicate (a person in a charge, crime, etc.).
4 include or affect in its operations.
5 (as involved adj.) a (often foll. by in) concerned or interested. b complicated in thought or form.
Etymology: ME f. L involvere involut- (as IN-(2), volvere roll)
Useful english dictionary. 2012.