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 decline from a sound or prosperous condition a decaying empire
2 : to decrease usually gradually in size, quantity, activity, or force The three voices … decayed and died out upon her ear.— Thomas Hardy
3 : to fall into ruin the city's decaying neighborhoods
4 : 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
5 : 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

transitive verb

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

decay

noun

Definition of decay (Entry 2 of 2)

1 : gradual decline in strength, soundness, or prosperity or in degree of excellence or perfection the decay of the public school system
2 : a wasting or wearing away : ruin a neighborhood that had fallen into decay
3 obsolete : destruction, death … sullen presage of your own decay.— Shakespeare
4a : 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
5 : a decline in health or vigor mental decay
6 : 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)

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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

The area -- which has been plagued by vagrancy, high crime rates and unsanitary conditions almost since its development in the 1880s -- is an unorganized collection of warehouses, wholesale storefronts and decaying low-rent hotels. Andrew O'reilly | Fox News, Fox News, "LA push to develop Skid Row prompts new clashes in California's homeless crisis," 14 July 2019 Today, this futuristic house is a decaying relic of the past, and its future is a subject of concern and conjecture. Mark Lamster, Dallas News, "The epic tale of the House of the Century, the trippy Texas icon that defies polite description," 12 July 2019 Flitting up behind enemy guards causes Hummingbird to automatically dispatch the goons with a sword, adding to a score multiplier that decays over time. Steven Strom, Ars Technica, "Never Stop Sneakin’ is a brilliant send-up of ’90s stealth games," 12 July 2018 These journeys—covering distances of up to five miles at speeds of around 20 miles per hour—will be powered by heat released by decaying plutonium-238 in a radioisotope thermoelectric generator (RTG), according to Vox’s Brian Resnick. Meilan Solly, Smithsonian, "NASA’s Dragonfly Mission Will Fly Through the Clouds of Titan, Saturn’s Biggest Moon," 28 June 2019 When parks are allowed to deteriorate, the decaying infrastructure and bad reputation of parks can turn them into magnets for crime. Lincoln Larson, The Conversation, "Can parks help cities fight crime?," 25 June 2019 What the group were interested in was the oil used in the binding medium, as this would have come from biological sources, such as seed oil, and would thus contain 14C that would have started decaying at the time the oil was produced. The Economist, "Researchers find a way to use minute samples to detect forged paintings," 8 June 2019 Even the promise of carbon-free electricity from hydropower has been undermined by revelations that decaying organic material in reservoirs releases methane, a potent greenhouse gas that contributes to global warming. Christina Nunez, National Geographic, "Hydropower, explained," 13 May 2019 The services that ever-rising taxes were supposed to pay for in these places—such as public schools, roads, commuter rail—have often stagnated or decayed. Mene Ukueberuwa, WSJ, "How Arlington Lured Amazon With Low Costs," 14 Dec. 2018

Recent Examples on the Web: Noun

In both 1987 and 2015, this feedback loop of decay ultimately affected more than 60 square miles of seagrass beds. Kate Stein, Scientific American, "Climate Change Throws a Wrench in Everglades Restoration," 21 June 2019 The islands in India’s Hugli River, in the Ganges estuary on the western edge of the Sundarbans region, illustrate advanced stages of the decay. Peter Schwartzstein, National Geographic, "This vanishing forest protects the coasts—and lives—of two countries," 17 June 2019 Archiving failures have left untold numbers of analog masters damaged and in states of decay. New York Times, "The Day the Music Burned," 11 June 2019 The Meat Puppets struggle against the laws of nature and forces of decay. Josh Wilbur, WIRED, "You Could Live Forever With This Sci-Fi Time Hack," 4 June 2019 RTGs provide power from the heat generated by this isotope’s decay, rather than splitting any atoms. John Wenz, Discover Magazine, "NASA's New Nuclear Reactor Could Change Space Exploration," 11 Feb. 2019 Unable to repair itself, the Y began its journey of decay. Quanta Magazine, "The Incredible Shrinking Sex Chromosome," 1 Dec. 2015 Usually, heat pipes funnel out heat that’s a byproduct of radioactive decay. John Wenz, Discover Magazine, "NASA's New Nuclear Reactor Could Change Space Exploration," 11 Feb. 2019 The decay is almost entirely through the whole trunk. John Benson, cleveland.com, "Lakewood forced to cut down rotting Summit Avenue Moses Cleaveland Tree," 19 Feb. 2018

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 1

Noun

15th century, in the meaning defined at sense 1

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

23 Jul 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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