from The American Heritage® Dictionary of the English Language, 5th Edition.

  • adjective Acting or producing effectively with a minimum of waste, expense, or unnecessary effort.
  • adjective Acting directly to produce an effect.
  • adjective Causing less waste or requiring less effort than comparable devices or methods. Used in combination.

from The Century Dictionary.

  • Producing outward effects; of a nature to produce a result; active; causative.
  • Acting or able to act with due effect; adequate in performance; bringing to bear the requisite knowledge, skill, and industry; capable; competent: as, an efficient workman, director, or commander.
  • Synonyms Efficacious, Effectual, etc. (see effective); energetic, operative, active, ready, helpful.
  • noun An efficient cause (see above).
  • noun One who is efficient or qualified; specifically, in the volunteer service of Great Britain, one who has attended the requisite number of drills, and in respect of whom the corps receives the capitation grant paid by government.
  • noun In mathematics, a quantity multiplied by another quantity to produce the quantity of which it is said to be an efficient; a factor.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective Causing effects; producing results; that makes the effect to be what it is; actively operative; not inactive, slack, or incapable; characterized by energetic and useful activity.
  • noun An efficient cause; a prime mover.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • adjective Making good, thorough, or careful use of resources; not consuming extra. Especially, making good use of time or energy.
  • adjective Using a particular proportion of available energy.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adjective able to accomplish a purpose; functioning effectively
  • adjective being effective without wasting time or effort or expense


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English, from Old French, from Latin efficiēns, efficient-, present participle of efficere, to effect; see effect.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

1398, "making," from Latin efficientem (nominative efficiens), preposition of efficere "work out, accomplish" (see effect). Meaning "productive, skilled" is from 1787. Efficiency apartment is first recorded 1930, American English.


Help support Wordnik (and make this page ad-free) by adopting the word efficient.



Log in or sign up to get involved in the conversation. It's quick and easy.

  • For some reason, this word sexually arouses me. I think it's because I like my men efficient. Efficient man, efficient sex, mm.

    June 23, 2007

  • You can learn so much on Wordie - & so efficiently.

    June 26, 2007

  • Uh huh...wait! Does efficient sex mean multiple orgasms? If not, maybe efficiency is not all it's cracked up to be...

    June 26, 2007

  • I miss Jacqueline. Every time I do something efficiently I think of her. I really do. (Sigh).

    September 24, 2007

  • efficient and sex would seem to be oxymoronic, though the Germans are said to be efficient lovers.

    September 24, 2007

  • This is one freaky thread.

    September 24, 2007

  • WORD: efficient


    ' This rambling introduction is four times as long as the most efficient, effective piece of writing in the history of the English-speaking world, which was Abraham Lincoln's address on the battlefield at Gettysburg. '

    1999 KURT VONNEGUT. God Bless You, Dr. Kevorkian. "Introduction" (Page 16).

    September 9, 2013