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 reductional (audio) , -​shə-​nᵊl \ adjective

Synonyms & Antonyms for reduction


abatement, deduction, discount


accession, addition

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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

That has helped spur a dramatic decrease in carbon dioxide emissions from power plants, the engine of U.S. emission reductions in recent years. Benjamin Storrow, Scientific American, "Proposed Energy Efficiency Rules Could Slow Emissions Reductions," 17 June 2019 And other operations, such as Huntsville's waste-to-energy incinerator, push the state over the 25 percent waste reduction goal. Dennis Pillion |,, "Alabama hits recycling milestone, keeping quarter of all trash from landfills," 16 June 2019 The environmental group assessed and ranked 20 grocers' plans to curb plastic shopping bags and packaging, and found that few retailers had plastic reduction goals or commitments to report their progress to the public. Paul Takahashi, Houston Chronicle, "Greenpeace: Grocers, particularly H-E-B, not doing enough to reduce plastics," 12 June 2019 Prakash-Mani said a global treaty on plastics and reduction targets from companies and governments was needed to tackle the issue. Isabelle Gerretsen, CNN, "You could be swallowing a credit card's weight in plastic every week," 11 June 2019 Nevertheless, the city sees it as an imperative part of meeting its waste reduction goals. Maggie Angst, The Mercury News, "Palo Alto to consider one of the Bay Area’s strictest bans of plastic straws, produce bags," 9 June 2019 The move comes as market participants grow more convinced that the Federal Reserve will likely cut rates later this year and follows a string of reductions by neighboring Asia-Pacific nations. Rachel Pannett, WSJ, "Australia Cuts Rates for the First Time in Nearly Three Years," 4 June 2019 Correction posted June 14, 2017 This article has been updated to reflect the mayor's recent expansion of the city's greenhouse gas reduction goal to achieve carbon neutrality by 2050. The Christian Science Monitor, "Corrections," 4 Mar. 2019 While California’s emissions have noticeably dropped since the state implemented its program less than a decade ago, only 20% of those reductions can be tied to cap and trade. Washington Post, "Progressive climate policy poised to pass in Oregon," 17 June 2019

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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Statistics for reduction

Last Updated

22 Jun 2019

Look-up Popularity

Time Traveler for reduction

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

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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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