from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Producing or capable of producing a desired effect. See Synonyms at effective.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. effective
from the GNU version of the Collaborative International Dictionary of English
- adj. Possessing the quality of being effective; productive of, or powerful to produce, the effect intended.
from The Century Dictionary and Cyclopedia
- Producing the desired effect; having power adequate to the purpose intended; effectual in operation or result.
- Synonyms Efficient, Effectual, etc. (see effective); active, operative, energetic.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. marked by qualities giving the power to produce an intended effect
- adj. producing or capable of producing an intended result or having a striking effect
From Latin efficāx, efficāc-, from efficere, to effect; see effect.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Old French efficacieux, from Latin efficax ("efficacious"), from efficere ("to effect, accomplish, to"); see effect. (Wiktionary)