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: dilapidation, degeneration, 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. Alsodisintegrate 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

/ dĭ-kā′ /

Noun

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

Verb

1. To undergo decay.

Derived Forms

• deˈcayable, adjective

Other Words From

• de·caya·ble adjective
• de·cayed·ness [dih-, keyd, -nis, -, key, -id-], adjective
• de·cayless adjective
• nonde·cayed adjective
• nonde·caying adjective
• rede·cay verb
• semi·de·cay noun
• semi·de·cayed adjective
• unde·caya·ble adjective
• unde·cayed adjective
• unde·caying 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

One memory decayed much faster than the other -- a form of memory loss necessary for habituation, the researchers noted.

From Science Daily

But if it has been used inappropriately or installed poorly, it might put stress on timbers, restrict air circulation and put them at risk of decaying.

From BBC

Fluoride - a naturally occurring mineral recognised to protect teeth against decay - is added to water supplies in many countries, including the US, where around 63% of the population have fluoridated water.

From BBC

But the dinosaur, encased in layers of sediment, is exempt from this endless cycle of growth and decay.

From Los Angeles Times

It means there are now 599 sites across the capital deemed at risk of neglect, decay or inappropriate development by the heritage group.

From BBC

Related Words

• blight
• corrosion
• decomposition
• degeneration
• deterioration
• disintegration
• disrepair
• extinction
• impairment
• rot