efficiency

noun

ef·fi·cien·cy | \ i-ˈfi-shən-sē

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

3 : efficiency apartment

Synonyms & Antonyms Example Sentences Learn More about efficiency

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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.

Recent Examples on the Web

Boulder County is promoting sustainability practices like energy efficiency and aims to cut emissions by 80 percent by 2050. — Umair Irfan, Vox, "Why Colorado thinks it has a chance to make oil companies pay for climate change," 5 July 2018 But under the new agreement, the utilities will aim to produce a minimum 25% of their energy from renewable sources and a further 25% from energy-efficiency measures by that same year. — Jason Hayes, WSJ, "A California Billionaire Sets Michigan’s Energy Policy," 22 June 2018 The agreements let customers borrow money to buy renewable energy systems or energy efficiency devices, then pay back the cash as part of their monthly utility bills. — Nathaniel Herz, Anchorage Daily News, "Juneau wrap-up, part 5: Lawmakers pass energy-efficiency loan legislation," 31 May 2018 Related: Photos of Green Roofs 1 / 9 View Images The $13 million energy-efficiency retrofit was completed in 2013, and the upgrades cut energy consumption by almost 40 percent, saving over $4 million annually. — National Geographic, "From Historic to Cutting Edge: Revitalizing Iconic Buildings," 25 May 2018 Rapidly declining prices for wind and solar power, energy efficiency initiatives and state renewable energy mandates are projected to cut even deeper into coal’s shrinking share of the energy mix. — Michael Hawthorne, chicagotribune.com, "EPA deal marks dramatic shift away from dirty coal power in Chicago area," 24 May 2018 McNeil had been working at the Learning Experience in Foxborough as a subcontractor for an energy efficiency company. — Fox News, "Police: Man hid recording device in preschool restroom," 23 May 2018 The mandate, approved 5-to-0 by the California Energy Commission, is part of the state's 2019 update of energy efficiency standards and ongoing efforts to reduce greenhouse gases. — Jeff Daniels, USA TODAY, "Rooftop solar to be required on new homes in California," 10 May 2018 On a call with analysts, bank executives fielded multiple questions about its efficiency goals. — Christina Rexrode, WSJ, "Citigroup Earnings Lifted by Growing Loans," 13 July 2018

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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Last Updated

12 Sep 2018

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Time Traveler for efficiency

The first known use of efficiency was in 1633

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More Definitions for efficiency

efficiency

noun

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 ( technical )

See the full definition for efficiency in the English Language Learners Dictionary

efficiency

noun

ef·fi·cien·cy | \ i-ˈfi-shən-sē

plural efficiencies