Definition of decay in English:

decay

Syllabification: de·cay
Pronunciation: /dəˈkā
 
/

verb

[no object]
1(Of organic matter) rot or decompose through the action of bacteria and fungi: (as adjective decayed) a decayed cabbage leaf (as adjective decaying) the odor of decaying fish
More example sentences
  • This is a fungus also caused by excess fish waste and food decaying in the bottom of the tank.
  • Organic material decays rapidly, especially in hot climes like that of Egypt, Evershed said.
  • Litter in years gone by was really non existent and not the problem it is today, as packaging was simple and brown paper bags being organic quickly decayed.
Synonyms
decompose, rot, putrefy, go bad, go off, spoil, fester, perish, deteriorate; degrade, break down, molder, shrivel, wither; photodegradedecomposed, decomposing, rotten, putrescent, putrid, bad, off, spoiled, far gone, perished; moldy, festering, fetid, rancid, rank; maggoty, wormydecomposing, decomposed, rotting, rotten, putrescent, putrid, bad, off, perished; moldy, festering, fetid, rancid, rank; maggoty, wormy
1.1 [with object] Cause to rot or decompose: the fungus will decay soft timber
More example sentences
  • The council said the fungi had decayed the roots.
  • I stand to inherit a water penetration problem, caused not by my countless tea drinking, but by water decaying the roof beams in the lounge.
  • It is easy for tiny amounts of food to get trapped in the tiny dents or fissures, and if you do not brush them thoroughly, bacteria can build up and start to decay the tooth.
1.2(Of a building or area) fall into disrepair; deteriorate: urban neighborhoods decay when elevated freeways replace surface roads
More example sentences
  • On the downside he's noticed that the urban infrastructure has decayed immeasurably in recent years.
  • For years Blackburn's Church Street Pavilions have been allowed to crumble and decay so that the Grade ll listed buildings have become nothing more than an eyesore.
  • A few suburbs have flourished, while the inner city has decayed and once relatively stable working class communities have deteriorated.
Synonyms
deteriorate, degenerate, decline, go downhill, slump, slide, go to rack and ruin, go to seed; disintegrate, fall to pieces, fall into disrepair; fail, collapse
informal go to pot, go to the dogs, go into/down the toilet
declining, degenerating, dying, crumbling, disintegrating; derelict, run-down, tumbledown, ramshackle, shabby, decrepit; in decline, in ruins, on the way out
1.3Decline in quality, power, or vigor: the moral authority of the party was decaying
More example sentences
  • But inevitably, a society acknowledging no transgenerational commitment to the future will decay and decline from within.
  • Without the instability of the declining 18th century, as the old European order decayed, we would not have gained the French assistance decisive to our struggle for independence.
  • Institutional inertia, social customs, and psychological habit ensure that systems can maintain their outer shapes long after they have begun to decay internally.
1.4 Physics (Of a radioactive substance, particle, etc.) undergo change to a different form by emitting radiation: the trapped radiocarbon begins to decay at a known rate
More example sentences
  • Some atoms can undergo radioactive beta decay, in which a neutron decays into a proton, an electron and an electron-antineutrino via the weak nuclear force.
  • Once solidified, the lead is ‘locked ‘in place and since the uranium decays to lead, the lead-to-uranium ratio increases with time.’
  • The uranium eventually decays to radium and, eventually to polonium - 210, a substance that, when inhaled, can endanger tissue health and damage the immune system.
1.5 technical (Of a physical quantity) undergo a gradual decrease: the time taken for the current to decay to zero
More example sentences
  • Since antibody affinity is expected to stay the same even in AIDS, unlike antibody quantity which decays in advanced disease, this approach is less likely to give false recent classification.
  • We found that fluorescence decayed with an averaged time constant of 142.8 s due to photobleaching.
  • LD decayed relatively slowly but steadily within genes.

noun

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1The state or process of rotting or decomposition: hardwood is more resistant to decay than softwood bacterial decay
More example sentences
  • There's a smell of vegetable decay.
  • The feedback, clipping, and heavy crackle due to vinyl decay doesn't do much justice as far as preservation goes.
  • The rate of product decay is increasing.
Synonyms
decomposition, putrefaction, festering; photodegradation; rot, mold, mildew, fungusrot, corrosion, decomposition; caries, cavities, holes
1.1Structural or physical deterioration: the old barn rapidly fell into decay
More example sentences
  • The home fell into decay by the start of the 1970s.
  • Gradually the abandoned buildings fell into decay or were adopted for other uses.
  • The home is still empty today, and has suffered considerable interior damage, including structural decay resulting from water leaks in the building.
Synonyms
deterioration, degeneration, debasement, degradation, decline, weakening, atrophy; crumbling, disintegration, collapse
1.2Rotten matter or tissue: fluoride heals small spots of decay
More example sentences
  • However, too much growth produces a strain on tissues and early decay.
  • When the decay reaches the pulp tissue, the blood vessels, and the nerves that serve the tooth, the pain starts - an insistent throbbing.
  • Layers of moss and decay give a funereal quality to this weighty hall.
1.3The process of declining in quality, power, or vigor: preachers warning of moral decay
More example sentences
  • ‘Together let us find solutions to moral decay by jointly developing a strategy and a programme of action,’ Masondo says.
  • People talk a lot about cultural decay and declining values and the blame is usually placed on evil liberals.
  • For Webster's audience, Italy was perceived as a site of political intrigue, economic power, decadence, and moral decay.
1.4 Physics The change of a radioactive substance, particle, etc., into another by the emission of radiation: the gas radon is produced by the decay of uranium in rocks and soil
More example sentences
  • The radioactive decay releases energy in the form of ionising radiation.
  • The principles of alpha decay are used in radioactive dating, in which half-lives play an important part.
  • Radon is present in the atmosphere because it is constantly being formed during the radioactive decay of uranium and radium.
1.5 technical Gradual decrease in the magnitude of a physical quantity: the decay of electrical fields in the electromagnets
More example sentences
  • After linear baseline subtraction, to account for the gradual decay of the synchrotron beam intensity, two kinds of treatments were performed.
  • Measurements of the decay of the electrical field across the thylakoid membrane following a light - dark transition might give some clues to this.
  • This is one order of magnitude slower than the decay of K in the bacteriorhodopsin photocycle.

Origin

late Middle English: from Old French decair, based on Latin decidere 'fall down or off', from de- 'from' + cadere 'fall'.

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