| 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" effective, effectual, 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" 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" 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" efficient - being effective without wasting time or effort or expense; "an efficient production manager"; "efficient engines save gas" potent, stiff, strong - having a strong physiological or chemical effect; "a potent toxin"; "potent liquor"; "a potent cup of tea", "a stiff drink" powerful - having great power or force or potency or effect; "the most powerful government in western Europe"; "his powerful arms"; "a powerful bomb"; "the horse's powerful kick"; "powerful drugs"; "a powerful argument" |