efficiency

noun

ef·​fi·​cien·​cy i-ˈfi-shən-sē How to pronounce efficiency (audio)
plural efficiencies
1
: the quality or degree of being efficient
2
a
: 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

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In an era when multinationals are diversifying away from single-market dependencies, Minister Al-Falih’s remarks made clear that Riyadh wants to anchor that shift — offering predictability, efficiency, and partnership in a volatile world. Dave Smith, Fortune, 26 Oct. 2025 For all of the perils of injecting it into the newsgathering process, AI tools have also come to be seen as useful and less-fraught ways to create efficiencies in editing, advertising and other areas. Dade Hayes, Deadline, 25 Oct. 2025 This flexibility enhances efficiency and effectiveness across multiple scenarios, from verifying and containing early-stage fires in remote terrain to supporting large-scale firefighting and cold trailing efforts on major incidents. Jijo Malayil, Interesting Engineering, 25 Oct. 2025 Those efficiencies are what make the Ford the most advanced carrier in the world and result from its two nuclear reactors, whose exact specs are classified but that put out three times the electrical power of those on the Nimitz-class ships, according to the Navy. Brad Lendon, CNN Money, 25 Oct. 2025 See All Example Sentences for efficiency

Word History

Etymology

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

First Known Use

1633, in the meaning defined at sense 1

Time Traveler
The first known use of efficiency was in 1633

Browse Nearby Words

Cite this Entry

“Efficiency.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/efficiency. Accessed 30 Oct. 2025.

Kids Definition

efficiency

noun
ef·​fi·​cien·​cy i-ˈfish-ən-sē How to pronounce efficiency (audio)
plural efficiencies
1
: the quality or degree of being efficient
2
: efficient operation
3
: the ratio of the useful energy delivered by a machine to the energy supplied to it

More from Merriam-Webster on efficiency

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