Efficacy
ahd-5
noun.
Power or capacity to produce a desired effect; effectiveness.
The Century Dictionary and Cyclopedia
noun.
The quality of being efficacious or effectual; production of, or the capacity of producing, the effect intended or desired; effectiveness.
noun.
Synonyms
Efficiency
, etc. (see
effectiveness
); virtue, force, energy.
the GNU version of the Collaborative International Dictionary of English
noun.
Power to produce effects; operation or energy of an agent or force; production of the effect intended
Wiktionary, Creative Commons Attribution/Share-Alike License
noun.
Ability to produce a desired amount of a desired
effect
.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
capacity or power to produce a desired effect