expulsion n.

c. 1400, expulsioun, in medicine, "act of expelling matter from the body," from Old French expulsion or directly from Latin expulsionem (nominative expulsio), noun of action from past-participle stem of expellere "drive out" (see expel). From late 15c. as "forcible ejection, compulsory dismissal, banishment" as from a school or club.