1. [ adjective ] 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"

Related terms: inefficacious effective effective efficacy
2. [ adjective ] producing or capable of producing an intended result or having a striking effect
Synonyms: effective effectual

"an air-cooled motor was more effective than a witch's broomstick for rapid transportation"-LewisMumford "effective teaching methods" "effective steps toward peace"

Related terms: ineffective impelling hard-hitting hard-hitting rough-and-ready impressive powerful useful efficient potent effectiveness
Similar spelling:   efficaciously