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

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 In cold water, bodies are slow to decay and may sink, especially in deep lakes. Rachael Lallensack, Smithsonian Magazine, 29 Oct. 2021 Well, to clean up, yes, but because the stuff really is supposed to decay and return nutrients to the soil, not get hauled off to the dump. Jeff Lowenfels, Anchorage Daily News, 7 Oct. 2021 For example, in 2020 the U.S. Air Force began a six-year project to develop a digital twin of a B-1B Lancer bomber to understand how individual parts decay, and how to slow those processes. Eleanor Cummins, Scientific American, 27 July 2021 Their collisions with gases make tiny particles named pions, which speedily decay into muons, subatomic blobs more than 200 times heavier than electrons. New York Times, 10 Nov. 2021 All the goodies in the above-ground parts of plants should be allowed to fall to the ground and decay over the winter. Jeff Lowenfels, Anchorage Daily News, 16 Sep. 2021 But an analysis posted earlier this month found that, if sterile neutrinos can decay into other, invisible particles, IceCube data actually favors their existence. Quanta Magazine, 28 Oct. 2021 When small fish start to decay, the bacterial flora in their guts burst through cell walls, initiating the process of autolysis. Taras Grescoe, Smithsonian Magazine, 23 Oct. 2021 After a few years of Alabama’s machine-like certainty, a nest of unknowns took root in the program at the point when the traditional lifecycle of a dynasty was set to decay. Michael Casagrande | Mcasagrande@al.com, al, 29 Sep. 2021 Recent Examples on the Web: Noun Any internal decay, no matter the tree species and how strong its wood, can drastically reduce load tolerance and lead to branch failure. Paul Cappiello, The Courier-Journal, 6 Jan. 2022 Rusak explores ephemerality, decay, and preservation in his work and has been experimenting with a material that mixes resin with plants and flowers so that the botanicals look almost like they’ve been trapped in amber. Diana Budds, Curbed, 17 Dec. 2021 Through the stories of generations of Chicago women, Turner gives a tutorial of urban decay, poor city planning, and the influence of fads and digital advances on Black urban teenagers. Washington Post, 18 Nov. 2021 The cheap, careworn hide suggests many things — neglect, decay, unraveling. Globe Staff, BostonGlobe.com, 11 Nov. 2021 Fluoride in drinking water is effective, safe and reduces and controls tooth decay and promotes oral health, according to the federal Centers for Disease Control and Prevention. Emily Goodykoontz, Anchorage Daily News, 16 Dec. 2021 And unlike fission reactors, there is no decay heat since there is little radioactivity in the fuel. James Conca, Forbes, 9 Nov. 2021 Old or loose dental fillings or tooth decay are also known to produce a metallic taste. Washington Post, 8 Oct. 2021 There’s help with oral care because long-term use of crystal meth can cause severe tooth decay and gum disease. Terry Demio, The Enquirer, 20 May 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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Dictionary Entries Near decay

Decauville

decay

decayable

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Statistics for decay

Last Updated

8 Jan 2022

Cite this Entry

“Decay.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/decay. Accessed 20 Jan. 2022.

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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.
: 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.
: 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

decay

intransitive verb
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)

More from Merriam-Webster on 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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