performing or functioning in the best possible manner with the least waste of time and effort; having and using requisite knowledge, skill, and industry; competent; capable: a reliable, efficient assistant.
satisfactory and economical to use: Our new air conditioner is more efficient than our old one.
producing an effect, as a cause; causative.
utilizing a particular commodity or product with the least waste of resources or effort (usually used in combination): a fuel-efficient engine.

Origin of efficient

1350–1400; Middle English (< Middle French) < Latin efficient- (stem of efficiēns), equivalent to ef- ef- + fic-, combining form of facere to make, do1 + -ent- -ent
Related formsef·fi·cient·ly, adverbnon·ef·fi·cient, adjectivenon·ef·fi·cient·ly, adverbqua·si-ef·fi·cient, adjectivequa·si-ef·fi·cient·ly, adverbsu·per·ef·fi·cient, adjectiveun·ef·fi·cient, adjective

Synonyms for efficient

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for efficient

Contemporary Examples of efficient

Historical Examples of efficient

  • Why did not your most efficient employers dispatch an ordinary assassin?

    The Leopard Woman

    Stewart Edward White

  • What this efficient cause is, is a question that awakens no responsive inquiry.

  • And all your Science you have turned to the efficient slaughter of men.

    The Harbor

    Ernest Poole

  • Thus we are led forward always from facts to their efficient causes.

    The Truth About Woman

    C. Gasquoine Hartley

  • Certainly, they115 are not so efficient as those of the older country; how could they be?

    Culture and Cooking

    Catherine Owen

British Dictionary definitions for efficient



functioning or producing effectively and with the least waste of effort; competent
philosophy producing a direct effect; causative
Derived Formsefficiently, adverb

Word Origin for efficient

C14: from Latin efficiēns effecting
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for efficient

"capable of producing the desired effect," late 14c., "making, producing immediate effect," from Old French efficient and directly from Latin efficientem (nominative efficiens) "effective, efficient, producing, active," present participle of efficere "work out, accomplish" (see effect). Meaning "productive, skilled" is from 1787. Related: Efficiently.

Online Etymology Dictionary, © 2010 Douglas Harper