Definition of: efficient

(i·fish′ənt) adjective
1. Acting or having power to act effectually; competent: an efficient leader.
2. Productive of effects; causative.
—noun
1. A qualified person; specifically, in the British Army, a volunteer certified for his qualifications.
2. An efficient cause. [<L efficiens, -entis, ppr. of efficere. See EFFECT.]
—ef·fi′cient·ly adverb Synonyms (adj.): effective, effectual, efficacious. That is effective which accomplishes an intended effect with emphasis, decision, and certainty; that is effectual which acts with such finality as to leave no more to be done. A person may be said to be efficient in general character or action; as, an efficient businessman; he may be called effective in some special relation; as, an effective speaker; the efficient person is habitually energetic, industrious, sagacious, and alert; a man may be an effective speaker on occasion who is not efficient in ordinary life. Efficacious and effectual are not used of persons. Antonyms: awkward, dull, feckless, feeble, fruitless, idle, ineffective, ineffectual, inefficacious, inefficient, inoperative, negligent, powerless, remiss, unavailing, useless, vain.