Synonyms of efficacious

1. efficacious (vs. inefficacious), effective, effective#1, effectual#1, efficacious: usage: 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"
2. effective (vs. ineffective), effectual, efficacious, hard-hitting, trenchant, impelling, impressive, telling, rough-and-ready, efficacious, efficient, potent#3, strong#4, stiff, powerful, useful#1, utile: usage: 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"