mindmap root((有效)) effective stresses the actual production or the power to produce an effect: an ~ rebuttal. effectual suggests the accomplishment of a desired result or the fulfillment of a purpose especially as viewed after the fact: the measures to halt crime proved ~. efficient suggests an acting or a potential for action or use in such a way as to avoid loss or waste of energy or resources in effecting, producing, or functioning: an ~ small car. efficacious suggests possession of a special quality or virtue that gives effective power: a detergent that is ~ in removing grease.