efficacious Meaning, Definition & Usage

  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
  2. adjective producing or capable of producing an intended result or having a striking effect
    effectual; effective.
    • 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

WordNet

Ef`fi*ca"cious adjective
Etymology
L. eficax, -acis, fr. efficere. See Effect, n.
Definitions
  1. Possessing the quality of being effective; productive of, or powerful to produce, the effect intended; as, an efficacious law. Syn. -- See Effectual. -- Ef`fi*ca"cious*ly, adv. -- Ef`fi*ca"cious*ness, n.

Webster 1913