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

On Labor Day, the body of 5-year-old Sierra Patino was found decaying in a closet in a Houston apartment. Harriet Sokmensuer, PEOPLE.com, "Boyfriend of Accused Mom Is Also Arrested in Case of 5-Year-Old Girl Found Decaying in Closet," 9 Sep. 2019 Without this, my biggest concern is that those historic buildings will sit there and decay without any resources to maintain them and that’s not a good outcome for anybody. Joe Rubino, The Denver Post, "Redevelopment of Loretto Heights could transform southwest Denver, this month City Council will weigh a plan that lays out that vision," 2 Sep. 2019 Physicists use it to predict the likelihood of a neutron decaying into a proton in a radioactive material. Sophia Chen, WIRED, "Why Big Banks Could Soon Jump on the Quantum Bandwagon," 26 July 2019 The grains incorporated trace amounts of radioactive potassium, which has steadily decayed into argon ever since, providing a clock that shows the landscape formed 60 million to 70 million years ago. Paul Voosen, Science | AAAS, "Dinosaur-age landscapes lurk in Southern Hemisphere," 26 June 2019 The Brooms stayed, Simon Broom died, and the family struggled to keep the ailing house together while the neighborhood decayed around them. Petula Dvorak, Washington Post, "A New Orleans family history: Big promises, dashed hopes and rising water," 30 Aug. 2019 Dead plants and animals no longer absorb carbon-14, and the trapped carbon starts to decay like clockwork. Michael Greshko, National Geographic, "Colossal volcano behind 'mystery' global cooling finally found," 23 Aug. 2019 Housing costs rose without giving black residents a stake in the value of their homes, while neighborhoods decayed from lack of investment. Calvin Schermerhorn, Twin Cities, "Calvin Schermerhorn: Why the racial wealth gap persists more than 150 years after emancipation," 27 June 2019 In experiments, prions have remained present and infectious two years after a carcass decays. al.com, "A deadly deer disease is spreading and could infect humans," 14 June 2019

Recent Examples on the Web: Noun

Even during that eight-hour window, the fruit is constantly temperature-controlled and monitored for respiration and other signs of decay. Julia Moskin, New York Times, "The World of Olive Oil Is Murky. Here’s Help for the Home Cook.," 30 Aug. 2019 The Internet has no weather, and these dissolving poems will be preserved in every state of decay. Dan Chiasson, The New Yorker, "Reader, I Googled It," 26 Aug. 2019 Expedition scientist Clare Fitzsimmons of Newcastle University tells Rebecca Morelle at the BBC that metal munching microbes are responsible for much of the decay. Jason Daley, Smithsonian, "The Titanic Is Being Reclaimed by the Sea," 22 Aug. 2019 Sheldon shrugged as a cluster of small frogs leapt among his rotting beans, seemingly impervious to the sharp stench of decay. NBC News, "Flooded out, farmers find work rebuilding the levees that failed them," 19 Aug. 2019 Edwards said officials went from room to room in the unit and found 41 live animals and more than 60 dead, in various stages of decay. Gage Miskimen, USA TODAY, "More than 100 exotic animals found hoarded in Iowa apartment — many of them dead," 15 Aug. 2019 Piles of broken concrete along the north edge of the route soon give way to patches of intact pavement in varying degrees of decay. Mare Czinar, azcentral, "Route 66 'ghost roads' hike: Walk in the vanishing path of the Mother Road," 1 Aug. 2019 Whole fruits and vegetables that show no signs of decay. Susan Selasky, Detroit Free Press, "Power out? Here's what to do with refrigerated and frozen foods," 22 July 2019 His paintings hold the rich colors of life — fuchsia, geranium red, gold — as well as the colors of decay — grey-yellow, beige, black. Nina Maclaughlin, BostonGlobe.com, "Bodies in detail, Kipling in Vermont, and Shakespeare in the park," 18 July 2019

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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Statistics for decay

Last Updated

17 Sep 2019

Look-up Popularity

Time Traveler for decay

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

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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)

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More from Merriam-Webster on decay

Rhyming Dictionary: Words that rhyme with decay

Thesaurus: All synonyms and antonyms for decay

Spanish Central: Translation of decay

Nglish: Translation of decay for Spanish Speakers

Britannica English: Translation of decay for Arabic Speakers

Britannica.com: Encyclopedia article about decay

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