re·​duc·​tion | \ ri-ˈdək-shən How to pronounce reduction (audio) \

Definition of reduction

1 : the act or process of reducing : the state of being reduced
2a : something made by reducing
b : the amount by which something is reduced
3 [Spanish reducción, from Latin reduction-, reductio] : a South American Indian settlement directed by Jesuit missionaries
4 : meiosis sense 2 specifically : production of the gametic chromosome number in the first meiotic division

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Other Words from reduction

reductional \ ri-​ˈdək-​shnəl How to pronounce reduction (audio) , -​shə-​nᵊl \ adjective

Synonyms & Antonyms for reduction



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Examples of reduction in a Sentence

a drastic reduction in size Many voters want to see some reduction of the deficit. There is a 20 percent reduction on selected items during this sale.
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Recent Examples on the Web Stopping inflation now will mean a sharp reduction and reform of entitlement spending programs, a far-reaching pro-growth tax reform, and no more bailouts and stimulus checks. Andrew Stuttaford, National Review, "Another Twist of the Knife: Introducing a New Death Tax," 1 May 2021 The health department reported a net reduction of 16 probable cases, likely meaning that they were confirmed with a molecular test. Bob Blubaugh,, "Carroll County no longer in ‘high’ COVID transmission category; one death reported," 30 Apr. 2021 Trump’s reduction in the top income tax rate for wealthy Americans, restoring it to 39.6% from 37%. Chris Megerian, Los Angeles Times, "Biden calls for sweeping actions as U.S. emerges from pandemic," 28 Apr. 2021 Possible scenarios include the reduction of the number of clubs per league (with Serie A potentially going from 20 to 18 teams) and the introduction of play-off and play-out rounds at the end of Serie A’s regular season. Daniele Proch, Forbes, "Italy’s Soccer Federation FIGC Approves ‘Anti-Super League’ Rule For Serie A Clubs," 27 Apr. 2021 The bottom 20% of taxpayers will receive a 20.4% boost in after-tax income and a $2,850 reduction in federal taxes, on average, from the relief law, according to the Tax Policy Center. Tami Luhby And Katie Lobosco, CNN, "Biden's stimulus delivered a bigger tax cut to lower-income Americans than the 2017 GOP reform, report shows," 26 Apr. 2021 Measures like these deserve top priority, not the facile and futile notion of carbon-dioxide emissions reduction, which Mr. Koonin rightly dismisses. WSJ, "Who Tells the Truth About Climate Change?," 23 Apr. 2021 Among the strongest pledges was the European Union's 55% reduction, which was codified into law on Tuesday. Scott Waldman, Scientific American, "U.S. Commits to Greater CO2 Reductions, China and India Do Not," 23 Apr. 2021 McGough voted against a $7 million reduction in the police overtime budget, a controversial decision that has split the City Council. Dallas News, "In District 10, Dallas City Council member Adam McGough faces challenge from small newspaper publisher," 22 Apr. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'reduction.' 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 reduction

15th century, in the meaning defined at sense 1

History and Etymology for reduction

Middle English reduccion restoration, from Middle French reducion, from Late Latin & Latin; Late Latin reduction-, reductio reduction (in a syllogism), from Latin, restoration, from reducere

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Time Traveler for reduction

Time Traveler

The first known use of reduction was in the 15th century

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Statistics for reduction

Last Updated

5 May 2021

Cite this Entry

“Reduction.” Dictionary, Merriam-Webster, Accessed 11 May. 2021.

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More Definitions for reduction



English Language Learners Definition of reduction

: the act of making something smaller in size, amount, number, etc. : the act of reducing something
: an amount by which something is reduced


re·​duc·​tion | \ ri-ˈdək-shən How to pronounce reduction (audio) \

Kids Definition of reduction

1 : the act of making something smaller or less : the state of being made smaller or less a reduction in noise
2 : the amount by which something is made smaller or less


re·​duc·​tion | \ ri-ˈdək-shən How to pronounce reduction (audio) \

Medical Definition of reduction

1 : the replacement or realignment of a body part in normal position or restoration of a bodily condition to normal
2 : the process of reducing by chemical or electrochemical means
3 : the psychological diminishment of emotion or needs through activity or adjustment
4 : meiosis specifically : production of the gametic chromosome number in the first meiotic division

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