late 15c., expedycius "useful, fitting," from Latin expeditus "disengaged, ready, convenient, prompt; unfettered, unencumbered," past participle of expedire (see expedite). Meaning "speedy, speedily accomplished" is from 1590s. Related: Expeditiously; expeditiousness.
expedient
expediently
expedite
expedition
expeditionary
expeditious
expel
expellee
expend
expendable
expenditure