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

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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.
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Recent Examples on the Web Customers are accustomed to falling prices, which have come from the better efficiency of larger turbines, scaling up manufacturing and industrializing installation. Rochelle Toplensky, WSJ, 16 July 2021 The partnership with Energy Star, and the resulting energy efficiency of Simonton Windows, is a source of many positive reviews. Madison Yauger, Better Homes & Gardens, 15 July 2021 But pro-government leaders and the party faithful doubled down, comparing the efficiency of the American and Chinese rescue efforts. Washington Post, 14 July 2021 Consumers can plug in information about their annual mileage and compare the fuel efficiency and emissions of electric cars with similar conventional models, using a tool from the U.S. Department of Energy. Deborah Sullivan Brennan, San Diego Union-Tribune, 6 July 2021 IoT applications improve the efficiency and effectiveness of supply chain management by reducing inventory inaccuracy and time to market. Forbes, 6 July 2021 Natalie Porat-Shliom, a cell biologist at the National Cancer Institute, suggests that one broad answer is that these social behaviors improve the efficiency of the whole organism. Quanta Magazine, 6 July 2021 That requires intense strength, which contributes to the efficiency of each step, an essential ingredient for any sprinter who does not possess the long strides of a tall sprinter. New York Times, 3 July 2021 Cuban officials last week said the vaccine has an efficiency of 92.28%. Star Tribune, 2 July 2021

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.

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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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Learn More About efficiency

Time Traveler for efficiency

Time Traveler

The first known use of efficiency was in 1633

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Statistics for efficiency

Last Updated

26 Jul 2021

Cite this Entry

“Efficiency.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/efficiency. Accessed 27 Jul. 2021.

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More Definitions for efficiency



English Language Learners Definition of efficiency

: the ability to do something or produce something without wasting materials, time, or energy : the quality or degree of being efficient


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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