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Synonyms

efficient

American  
[ih-fish-uhnt] / ɪˈfɪʃ ənt /

adjective

  1. 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.

    Synonyms:
    effectual
  2. satisfactory and economical to use.

    Our new air conditioner is more efficient than our old one.

  3. producing an effect, as a cause; causative.

  4. utilizing a particular commodity or product with the least waste of resources or effort (usually used in combination).

    a fuel-efficient engine.


efficient British  
/ ɪˈfɪʃənt /

adjective

  1. functioning or producing effectively and with the least waste of effort; competent

  2. philosophy producing a direct effect; causative

"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

Usage

What are other ways to say efficient? A person or a thing that is efficient performs or functions in the best possible manner with the least waste of time and effort. But efficient isn’t quite the same as effectual, efficacious, or effective! Find out why on Thesaurus.com. 

Other Word Forms

Derived Forms

Etymology

Origin of efficient

First recorded in 1350–1400; Middle English, from Middle French, from Latin efficient- (stem of efficiēns ), equivalent to ef- ef- + fic-, combining form of facere “to make, do 1 ” + -ent- -ent

Explanation

The adjective efficient describes function and use with the least amount of waste and most economy. When you want to define the adjective efficient, it's a good idea to say as much as you can in as few words as possible because to be efficient is to be economical and avoid waste in actions or uses. The word comes from the Latin efficientem which means "work out" or "accomplish." Synonyms of efficient are effective, productive, and competent.

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Vocabulary lists containing efficient

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Officials describe the update as a modernization effort intended to streamline outdated or redundant classifications and create a more efficient system for supporting service members’ religious needs.

From Salon • Jun. 6, 2026

To be an efficient cushion for countries and companies, however, stockpiles need to be at “Goldilocks” levels: not too much, not too little.

From MarketWatch • Jun. 6, 2026

The rotating vortex draws in large amounts of oxygen, creating a hotter and more efficient flame.

From Science Daily • Jun. 5, 2026

But eliminating the gag rule won’t impede the SEC’s mission to protect against fraud and to maintain fair, efficient markets.

From Barron's • Jun. 3, 2026

Briony imagined that retreating footsteps in the wide polished corridors had a muffled, apologetic sound, where once they had been bright and efficient.

From "Atonement" by Ian McEwan

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