decay

[dih-key]

verb (used without object)

1. to become decomposed; rot.

   vegetation that was decaying.

   Synonyms: putrefy, wither, degenerate

2. to decline in excellence, prosperity, health, etc.; deteriorate.

3. Physics.,  (of a radioactive nucleus) to change spontaneously into one or more different nuclei in a process in which atomic particles, as alpha particles, are emitted from the nucleus, electrons are captured or lost, or fission takes place.

verb (used with object)

1. to cause to decay or decompose; rot.

   The dampness of the climate decayed the books.

noun

1. decomposition; rot.

   Decay made the wood unsuitable for use.

   Synonyms: putrefaction

2. a gradual falling into an inferior condition; progressive decline.

   the decay of international relations; the decay of the Aztec civilizations.

3. decline in or loss of strength, health, intellect, etc..

   His mental decay is distressing.

   Synonyms: degeneration, dilapidation, impairment, decadence, deterioration

4. Physics.,  radioactive decay.

5. Aerospace.,  the progressive, accelerating reduction in orbital parameters, particularly apogee and perigee, of a spacecraft due to atmospheric drag.

decay

/ dɪˈkeɪ /

verb

1. to decline or cause to decline gradually in health, prosperity, excellence, etc; deteriorate; waste away

2. to rot or cause to rot as a result of bacterial, fungal, or chemical action; decompose

3. Also: disintegrate. (intr) physics

   1. (of an atomic nucleus) to undergo radioactive disintegration

   2. (of an elementary particle) to transform into two or more different elementary particles

4. (intr) physics (of a stored charge, magnetic flux, etc) to decrease gradually when the source of energy has been removed

noun

1. the process of decline, as in health, mentality, beauty, etc

2. the state brought about by this process

3. decomposition, as of vegetable matter

4. rotten or decayed matter

   the dentist drilled out the decay

5. physics

   1. See radioactive decay

   2. a spontaneous transformation of an elementary particle into two or more different particles

   3. of an excited atom or molecule, losing energy by the spontaneous emission of photons

6. physics a gradual decrease of a stored charge, magnetic flux, current, etc, when the source of energy has been removed See also time constant

7. music the fading away of a note

decay

1. The breaking down or rotting of organic matter through the action of bacteria, fungi, or other organisms; decomposition.

2. The spontaneous transformation of a relatively unstable particle into a set of new particles. For example, a pion decays spontaneously into a muon and an antineutrino. The decay of heavy or unstable atomic nuclei (such as uranium or carbon-10) into more stable nuclei and emitted particles is called radioactive decay. The study of particle decay is fundamental to subatomic physics.

3. See more at fundamental force radioactive decay

1. To undergo decay.

Other Word Forms

• decayable adjective
• decayedness adjective
• decayless adjective
• nondecayed adjective
• nondecaying adjective
• redecay verb
• semidecay noun
• semidecayed adjective
• undecayable adjective
• undecayed adjective
• undecaying adjective

Word History and Origins

Origin of decay¹

First recorded in 1425–75; late Middle English verb decayen, decaien, from Old North French decair, equivalent to de- “down” + cair “to fall,” from unattested Vulgar Latin cadēre, for Latin cadere; noun derivative of the verb; de-.

Word History and Origins

Origin of decay¹

C15: from Old Northern French decaïr, from Late Latin dēcadere, literally: to fall away, from Latin cadere to fall

Synonym Study

Decay, decompose, disintegrate, rot imply a deterioration or falling away from a sound condition. Decay implies either entire or partial deterioration by progressive natural changes: Teeth decay. Decompose suggests the reducing of a substance to its component elements: Moisture makes some chemical compounds decompose. Disintegrate emphasizes the breaking up, going to pieces, or wearing away of anything, so that its original wholeness is impaired: Rocks disintegrate. Rot is a stronger word than decay and is especially applied to decaying vegetable matter, which may or may not emit offensive odors: Potatoes rot.

Example Sentences

She said she had suffered from teeth and gum decay, mobility issues and chronic fatigue.

From BBC

We walked through tree branches, tangled vines and sharp hanging stalactites, over roots as thick as a human leg, and carcasses of birds, mice and God knows what else in varying states of decay.

From Salon

Uswayford is already past what Forestry England considers its optimum felling period, with some of the timber decaying on the ground following storm damage.

From BBC

"There are repercussions when it comes to an extraction-based therapy," she said, explaining remaining teeth move into the space, or there could be further tooth decay, which can cause other jaw problems.

From BBC

Working this way requires a deep sensitivity to subtlety, to decay, resonance, extremes, and to how sound lives after it’s been struck.

From Los Angeles Times

Related Words

• atrophy 
• corrode 
• decompose 
• degenerate 
• discolor 
• disintegrate 
• dissolve 
• dwindle 
• fade 
• get worse www.thesaurus.com
• lessen 
• mortify 
• pollute 
• rot 
• shrivel 
• wane 
• wither