Efficacious

a.

1.

Possessing the quality of being effective; productive of, or powerful to produce, the effect intended; as, an efficacious law.

Adj.	1.	efficacious - marked by qualities giving the power to produce an intended effect; "written propaganda is less efficacious than the habits and prejudices...of the readers"-Aldous Huxley; "the medicine is efficacious in stopping a cough" Antonyms: inefficacious - lacking the power to produce a desired effect; "laws that are inefficacious in stopping crime"
	2.	efficacious - producing or capable of producing an intended result or having a striking effect; "an air-cooled motor was more effective than a witch's broomstick for rapid long-distance transportation"-LewisMumford; "effective teaching methods"; "effective steps toward peace"; "made an effective entrance"; "his complaint proved to be effectual in bringing action"; "an efficacious law" Synonyms: effective, effectual

able, active, adequate, authoritative, capable, charismatic, charming, competent, consequential, effective, effectual, efficient, enchanting, equal to, estimable, functional, go, important, influential, magnetic, momentous, operational, operative, personable, persuasive, potent, powerful, practical, prestigious, productive, proficient, puissant, reputable, serviceable, strong, suasive, substantial, successful, telling, up to, useful, virtuous, weighty, winning