decay

verb
de·​cay | \ di-ˈkā How to pronounce decay (audio) \
decayed; decaying; decays

Definition of decay

 (Entry 1 of 2)

intransitive verb

1 : to undergo decomposition decaying fruit Her teeth were decaying. … most isotopes of copper decay quickly, but two are stable: Cu-63 and Cu-65.— David E. Thomas
2 : to decline in health, strength, or vigor Her mind is beginning to decay with age. believes that the moral fiber of our society is decaying
3 : to fall into ruin the city's decaying neighborhoods
4 : to decline from a sound or prosperous condition a decaying empire
5 : to decrease usually gradually in size, quantity, activity, or force The three voices … decayed and died out upon her ear.— Thomas Hardy

transitive verb

1 : to destroy by decomposition wood decayed by bacteria
2 obsolete : to cause to decay : impair Infirmity, that decays the wise …— William Shakespeare

decay

noun

Definition of decay (Entry 2 of 2)

1a : rot The material is … resistant to fire, decay and termites …— Jack McClintock specifically : aerobic decomposition of proteins chiefly by bacteria
b : the product of decay tooth decay
2 : gradual decline in strength, soundness, or prosperity or in degree of excellence or perfection the decay of the public school system
3 : a decline in health or vigor mental decay
4 : a wasting or wearing away : ruin a neighborhood that had fallen into decay
5 : decrease in quantity, activity, or force: such as
a chemistry : spontaneous decrease in the number of radioactive atoms in radioactive material
b physics : spontaneous disintegration (as of an atom or a particle)
6 obsolete : destruction, death … sullen presage of your own decay.— Shakespeare

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Other Words from decay

Verb

decayer noun

Choose the Right Synonym for decay

Verb

decay, decompose, rot, putrefy, spoil mean to undergo destructive dissolution. decay implies a slow change from a state of soundness or perfection. a decaying mansion decompose stresses a breaking down by chemical change and when applied to organic matter a corruption. the strong odor of decomposing vegetation rot is a close synonym of decompose and often connotes foulness. fruit was left to rot in warehouses putrefy implies the rotting of animal matter and offensiveness to sight and smell. corpses putrefying on the battlefield spoil applies chiefly to the decomposition of foods. keep the ham from spoiling

Examples of decay in a Sentence

Verb the smell of decaying rubbish dead plants and leaves decayed by bacteria She believes that the moral fiber of our society is decaying. our decaying public school system The city's neighborhoods are decaying. Noun the decay of dead plants and leaves She writes about the moral decay of our society. the patient's physical and mental decay The city's neighborhoods are in slow decay.
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Recent Examples on the Web: Verb Royalty payments are high soon after a song is released and then quickly decay. Carol Ryan, WSJ, "Older Artists Are the Havens of Music Investing," 5 Apr. 2021 One of the world’s largest wooden buildings, Turkey’s Prinkipo Orphanage, could be rescued from rot and decay and transformed into an environmental research center, reports Ayla Jean Yackley for the Art Newspaper. Livia Gershon, Smithsonian Magazine, "Preservationists Rally to Save Abandoned Casino-Turned-Orphanage in Istanbul," 7 Dec. 2020 Our stations are made of decay-resistant redwood and will provide years of trouble-free feeding. Popular Mechanics Editors, Popular Mechanics, "An Avian Feast: 3 Bird Feeders You Can Build For Your Backyard," 17 Apr. 2021 But, weirdly, legacy is tricky, and learning the bad doesn’t always decay the good. USA Today, "Trying to understand Kobe Bryant's complicated legacy a year after his death," 21 Jan. 2021 Slightly milder air is trickling into the area, mostly as our previously chilly air mass continues to decay. Washington Post, "P.M. Update: Rain develops toward sunrise, then continues off and on for much of Thursday," 17 Mar. 2021 Whatever composite particle arises will then inevitably decay through the weak interaction into a set of particles where that heavy quark has transformed into lighter quark. Ethan Siegel, Forbes, "Ask Ethan: Could An Unexplained Decay At The LHC Demolish The Standard Model?," 12 Mar. 2021 The mixture is also laden with naturally occurring radioactive elements that have been buried in the earth for millions of years, including uranium and thorium, which both decay into isotopes of radium. Eliza Griswold, The New Yorker, "When the Kids Started Getting Sick," 2 Mar. 2021 But whereas bones can take decades to decay, soft features, such as eyes, gills and organs, can disappear in a matter of months, weeks and even days. Katherine Harmon, Scientific American, "Rotting Fish Spoil Ideas about Early Life-Forms' Simplicity," 31 Jan. 2010 Recent Examples on the Web: Noun Their work involved the decay of particles called B-mesons into electrons, muons and their antimatter equivalents. The Economist, "Particle physics A second possible break in the laws of physics has been noted," 7 Apr. 2021 Venezuela is mired in one of the world’s worst humanitarian crises under Mr. Maduro, who, through a mix of corruption and neglect, oversaw the decay of the country’s oil infrastructure that had propped up its economy. Lara Jakes, New York Times, "Biden Gives Venezuelans Reprieve to Remain in U.S. Trump Had Rejected," 8 Mar. 2021 Who, Hardin asks, ought to shoulder responsibility for the costs of pollution, health risks, environmental decay, erosion, waste, pain caused by faulty products and the worsening environmental situation? Dennis Jaffe, Forbes, "From Shareholder Primacy To Stakeholder Primacy: How Family Businesses Lead The Way," 24 Feb. 2021 In the eyes of President Donald Trump and some Republicans, electing the Democrats in 2020 would lead to a clear and frightening outcome: tranquil suburbs in Connecticut and elsewhere would be overrun by crime, violent protests, and social decay. Eliza Fawcett, courant.com, "Unrest in Avon? Trump’s message of law and order, loaded with racist undertones, takes aim at safety and security in Connecticut suburbs," 14 Oct. 2020 Blowflies, linked in the public mind to death, decay and forensic examination of corpses, have a much bigger image problem. Stephanie Pain, Smithsonian Magazine, "How Much Do Flies Help With Pollination?," 8 Mar. 2021 But be sure to avoid those with gills that are matted with moisture, which could signal decay and off flavors. Star Tribune, "Portobellos pack a punch as a meal on their own," 16 Dec. 2020 Without ever coalescing, the book adds up (sort of) to a meditation on decay and dying and death, phenomena that Mr. Amis has witnessed, up close, in several of his life’s most important people. Thomas Mallon, WSJ, "‘Inside Story’ Review: Life, Unplotted," 16 Oct. 2020 The corresponding decay pathways must all be allowed. Ethan Siegel, Forbes, "Ask Ethan: Could An Unexplained Decay At The LHC Demolish The Standard Model?," 12 Mar. 2021

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

Verb

15th century, in the meaning defined at intransitive sense 4

Noun

15th century, in the meaning defined at sense 2

History and Etymology for decay

Verb and Noun

Middle English, from Anglo-French decaïr, from Late Latin decadere to fall, sink, from Latin de- + cadere to fall — more at chance

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Time Traveler for decay

Time Traveler

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

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Statistics for decay

Last Updated

8 May 2021

Cite this Entry

“Decay.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/decay. Accessed 13 May. 2021.

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More Definitions for decay

decay

verb

English Language Learners Definition of decay

 (Entry 1 of 2)

: to be slowly destroyed by natural processes : to be slowly broken down by the natural processes that destroy a dead plant or body
: to slowly lose strength, health, etc.
of a building, area, etc. : to go slowly from a bad condition to a worse condition : to slowly enter a state of ruin

decay

noun

English Language Learners Definition of decay (Entry 2 of 2)

: the process or result of being slowly destroyed by natural processes
: the slow loss of strength, health, etc.
of a building, area, etc. : the process or result of going slowly from a bad condition to a worse condition

decay

verb
de·​cay | \ di-ˈkā How to pronounce decay (audio) \
decayed; decaying

Kids Definition of decay

 (Entry 1 of 2)

1 : to break down or cause to break down slowly by natural processes Fruit decayed on the ground. Sugar decays teeth.
2 : to slowly worsen in condition The old theater decayed.

decay

noun

Kids Definition of decay (Entry 2 of 2)

1 : the process or result of slowly breaking down by natural processes The schoolhouse being deserted soon fell to decay— Washington Irving, “Sleepy Hollow”
2 : a gradual worsening in condition a decay in manners
3 : a natural change of a radioactive element into another form of the same element or into a different element
de·​cay | \ di-ˈkā How to pronounce decay (audio) \

Medical Definition of decay

 (Entry 1 of 2)

: to undergo decomposition

transitive verb

: to destroy by decomposition

decay

noun

Medical Definition of decay (Entry 2 of 2)

1a : rot sense 1 specifically : aerobic decomposition of proteins chiefly by bacteria
b : the product of decay
2a : spontaneous decrease in the number of radioactive atoms in radioactive material
b : spontaneous disintegration (as of an atom or a nuclear particle)

Comments on decay

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