early 15c., expedicioun, "military campaign; the act of rapidly setting forth," from Old French expedicion "an expediting, implementation; expedition, mission" (13c.) and directly from Latin expeditionem (nominative expeditio) "an enterprise against an enemy, a military campaign," noun of action from past-participle stem of expedire "make ready, prepare" (see expedite). Meaning "journey for some purpose" is from 1590s. Sense by 1690s also included the body of persons on such a journey.