Inherent capacity for growth and development; potentiality.
The ratio of the energy delivered by a machine to the energy supplied for its operation.
(Psychol.) An emotion or feeling attached to an idea, object, etc.
(Cinematography) An illusion produced by technical means (as in "special effect")
The condition or fact of being insufficient or falling short:
An inefficient act, design, or procedure:
Find another word for efficacy. In this page you can discover 29 synonyms, antonyms, idiomatic expressions, and related words for efficacy, like: effectiveness, potency, ability, productiveness, effectuality, efficiency, inefficacy, impotency, efficaciousness, affect and usefulness.