1.reduction in size of an organ or part (as in the return of the uterus to normal size after childbirth)
2.a long and intricate and complicated grammatical construction
3.marked by elaborately complex detail
4.the act of sharing in the activities of a group;
the teacher tried to increase his students' engagement in class activities
5.the process of raising a quantity to some assigned power
6.the action of enfolding something