efficiency
Americannoun
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the state or quality of being efficient, or able to accomplish something with the least waste of time and effort; competency in performance.
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accomplishment of or ability to accomplish a job with a minimum expenditure of time and effort.
The assembly line increased industry's efficiency.
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the ratio of the work done or energy developed by a machine, engine, etc., to the energy supplied to it, usually expressed as a percentage.
noun
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the quality or state of being efficient; competence; effectiveness
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the ratio of the useful work done by a machine, engine, device, etc, to the energy supplied to it, often expressed as a percentage See also thermal efficiency
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The ratio of the energy delivered (or work done) by a machine to the energy needed (or work required) in operating the machine. The efficiency of any machine is always less than one due to forces such as friction that use up energy unproductively.
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See also mechanical advantage
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The ratio of the effective or useful output to the total input in any system.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of efficiency
First recorded in 1585–95; from Latin efficientia, from efficient- (stem of efficiēns efficient ) + -ia -y 3
Explanation
Efficiency is avoiding a waste of time, effort, or resources. Many people have begun to use compact fluorescent light bulbs because of their greater energy efficiency. Nowadays, efficiency often refers to energy efficiency, the effort to get more energy from existing resources: making cars that can go farther with less fuel, or appliances that do the same work with less electricity. But this noun isn't restricted to an environmental context. Efficiency can also simply be a measurement of what goes into a thing versus what comes out of it. A process with high efficiency requires only a little work to produce big results.
Vocabulary lists containing efficiency
Word Generation Science - Energy
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"The Veldt" by Ray Bradbury
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The Boy in the Striped Pajamas
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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.
See Examples For:
Musk said capital efficiency is not the only priority.
From Barron's ● Jul. 22, 2026
Much of this will stem from technological improvements and innovation, the implementation of blockchain for faster settlement and the adoption of AI for efficiency and productivity.
From MarketWatch ● Jul. 22, 2026
Increasing triplet generation efficiency could improve photoredox and environmental catalysis.
From Science Daily ● Jul. 22, 2026
In response, the media giants argued that the states had misread the market and that merging would improve streaming efficiency.
From BBC ● Jul. 20, 2026
She was tired, not just from being pregnant and from the lockdown but from the unpleasant phone call she’d just had with corporate about ways to increase efficiency, which really meant ways to save money.
From "Not Nothing" by Gayle Forman
Unsurprisingly, both Larry and David Ellison are big fans of artificial intelligence, seeing it as a way to streamline their surveillance operations, and for what David Ellison euphemistically calls “cost efficiencies and synergies.”
From Salon ● Jul. 20, 2026
Hou drew comparisons to last year’s DeepSeek moment, which caused Nvidia and other chip stocks to tumble on fears that compute efficiencies would reduce demand for AI infrastructure.
From MarketWatch ● Jul. 17, 2026
It also expects savings from accelerating the use of Artificial Intelligence, with around £50m a year of "digital" efficiencies.
From BBC ● Jul. 1, 2026
Higher uptake of ASML’s most advanced lithography machines will allow the company to take a greater share of clients’ spending, while manufacturing efficiencies will increase profit margins, the analysts say.
From The Wall Street Journal ● Jun. 23, 2026
Having absorbed Lawrence’s confidence that further efficiencies eventually would be achieved, Groves reduced the specification for Y-12 to five hundred tanks, or five racetracks.
From "Big Science" by Michael Hiltzik
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
