ef·​fi·​cien·​cy | \ i-ˈfi-shən-sē How to pronounce efficiency (audio) \
plural efficiencies

Definition of efficiency

1 : the quality or degree of being efficient
2a : efficient operation
b(1) : effective operation as measured by a comparison of production with cost (as in energy, time, and money)
(2) : the ratio of the useful energy delivered by a dynamic system to the energy supplied to it

Examples of efficiency in a Sentence

Because of her efficiency, we got all the work done in a few hours. The factory was operating at peak efficiency. A furnace with 80 percent fuel efficiency wastes 20 percent of its fuel. The company is trying to lower costs and improve efficiencies.
Recent Examples on the Web Most people would begin to think about solutions by shopping around for the necessary materials but not Amory Lovins, the renowned energy efficiency advocate. Leidy Klotz, Scientific American, 12 May 2022 Public information officer Abby Pavlik said the department recently received several reports of people going door to door inquiring about home energy efficiency. Evan Casey, Milwaukee Journal Sentinel, 10 May 2022 Jokic also posted the highest player efficiency rating – a measurement of a player’s positive and negative contributions -- in league history at 32.85, according to basketball-reference.com. Jeff Zillgitt, USA TODAY, 9 May 2022 Stroud finished in the top five nationally in touchdown passes (44), completion percentage (71.9), passer efficiency rating (186.6), yards/game (369.9) and yards/attempt (10.1) and QBR (91.6) as a red-shirt freshman. Eddie Brown, San Diego Union-Tribune, 5 May 2022 Two rules setting stricter efficiency standards will effectively phase out sales of incandescent bulbs, in an effort to save consumers money and cut greenhouse gas emissions. New York Times, 29 Apr. 2022 The proposal recommended changes in energy efficiency, electricity supply, industrial energy requirements, transportation and natural gas. Stephen Singer, Hartford Courant, 27 Apr. 2022 Energy efficiency standards were part of legislation approved during George W. Bush's reign, and then picked up by the Obama administration. Kate Gibson, CBS News, 27 Apr. 2022 Additionally intriguing is the fact that the 7-footer canned 41 three-pointers at 39% efficiency, and has shown capabilities as a ball-handler and play initiator. Morten Jensen, Forbes, 30 Apr. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'efficiency.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of efficiency

1633, in the meaning defined at sense 1

History and Etymology for efficiency

borrowed from Latin efficientia, from efficient-, efficiens "producing or giving rise to something, immediate (of a cause), efficient" + -ia -y entry 2

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Time Traveler for efficiency

Time Traveler

The first known use of efficiency was in 1633

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Dictionary Entries Near efficiency



efficiency apartment

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Statistics for efficiency

Last Updated

15 May 2022

Cite this Entry

“Efficiency.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/efficiency. Accessed 26 May. 2022.

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More Definitions for efficiency


ef·​fi·​cien·​cy | \ i-ˈfi-shən-sē How to pronounce efficiency (audio) \
plural efficiencies

Kids Definition of efficiency

: the ability to do something or produce something without waste

More from Merriam-Webster on efficiency

Nglish: Translation of efficiency for Spanish Speakers

Britannica English: Translation of efficiency for Arabic Speakers

Britannica.com: Encyclopedia article about efficiency


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