producing or capable of producing an intended effect; adequate.

valid or binding, as an agreement or document.

adjective

impotent , incapable , ineffectual , unproductive , unsuccessful , useless , weak

adjective

accomplishing , achieving , adequate , binding , capable , conclusive , decisive , determinative , effecting , effective , efficacious , efficient , forcible , fulfilling , in force , lawful , legal , licit , potent , powerful , practicable , productive , qualified , serviceable , sound , strong , successful , telling , useful , valid , virtuous , workablenotes:effective means \'having a (desired) result or effect , \' effectual is \'succeeding in producing a desired result or effect , \' and efficacious means the same as effectual as well as \'serving as an effective solution or remedy\' , authoritative , availing , functional , influential