"incapable of producing result," 1550s, from Middle French futile or directly from Latin futilis, futtilis "vain, worthless, futile," a figurative use, literally "pouring out easily, easily emptied" (the Latin adjective used as a noun meant "a water vessel broad above and pointed below"), hence "leaky, unreliable," from fundere "to pour, melt," from PIE root *gheu- "to pour" (see found, v.2). Related: Futilely.