Origin: 1350–1400; Middle English Related forms
< Latin effectīvus
practical, equivalent to effect
), past participle of efficere
) + -īvus -ive
effectiveness, effectivity, noun
Can be confused: affective
(see synonym study at the current entry).
1. capable, competent. Effective, effectual, efficacious, efficient refer to that which is able to produce a (desired) effect. Effective is applied to that which has the power to, or which actually does, produce an effect: an effective action, remedy, speech. Effectual is used especially of that which produces the effect desired or intended, or a decisive result: An effectual bombardment silenced the enemy. Efficacious suggests the capability of achieving a certain end: an efficacious plan, medicine. Efficient (applied also to persons) implies the skillful use of energy or industry to accomplish desired results with little waste of effort: efficient methods; an efficient manager. 2. operative. 3. telling.
1. futile, useless.