decay

[ dih-key ]

/ dɪˈkeɪ /

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See synonyms for: decay / decayed / decaying on Thesaurus.com

verb (used without object)

to become decomposed; rot: vegetation that was decaying.

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

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)

to cause to decay or decompose; rot: The dampness of the climate decayed the books.

noun

decomposition; rot: Decay made the wood unsuitable for use.

a gradual falling into an inferior condition; progressive decline: the decay of international relations; the decay of the Aztec civilizations.

decline in or loss of strength, health, intellect, etc.: His mental decay is distressing.

Physics. radioactive decay.

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

OTHER WORDS FOR decay

1 degenerate, wither; putrefy.

5 putrefaction.

7 deterioration, decadence, impairment, dilapidation, degeneration.

See synonyms for decay on Thesaurus.com

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Origin of decay

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; see de-.

synonym study for decay

1. 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.

OTHER WORDS FROM decay

de·cay·a·ble, adjectivede·cayed·ness

[dih-keyd-nis, -key-id-], /dɪˈkeɪd nɪs, -ˈkeɪ ɪd-/, adjectivede·cay·less, adjectivenon·de·cayed, adjective

non·de·cay·ing, adjectivere·de·cay, verbsem·i·de·cay, nounsem·i·de·cayed, adjectiveun·de·cay·a·ble, adjectiveun·de·cayed, adjectiveun·de·cay·ing, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use decay in a sentence

The best way to estimate the age of a planet’s surface is to analyze its rocks, using the radioactive decay of its elements as a geologic clock.
Rumbles on Mars Raise Hopes of Underground Magma Flows|Robin George Andrews|February 1, 2021|Quanta Magazine
The researchers hoped to use it to simulate false vacuum decay and bubble collisions.
How Universes Might Bubble Up and Collide - Facts So Romantic|Charlie Wood|January 28, 2021|Nautilus
Planets heated their original rocks with the decay of radioactive elements, collisions with asteroids or other planets, and with the leftover heat of their own formation.
Crushed space rocks hint at exoplanets’ early atmospheric makeup|Lisa Grossman|January 26, 2021|Science News
A limited quantum computer, it specializes in solving optimization problems by letting qubits seek out the lowest-energy configuration available — a process not unlike false vacuum decay.
Physicists Study How Universes Might Bubble Up and Collide|Charlie Wood|January 25, 2021|Quanta Magazine

Because for every hydrocarbon atom that goes into the Earth, an oxygen atom is not used up in the decay process.
Why Birds Can Fly Over Mount Everest - Issue 94: Evolving|Walter Murch|December 30, 2020|Nautilus
An early autumn sun lit up cobblestone streets, tall acacia trees, and handsome and nearly all decayed 19th-century buildings.
Great Weekend Reads|The Daily Beast|March 5, 2011|DAILY BEAST
This may be the region where Islam was born, but it is also the place where Islam has lately festered and decayed.
Why Obama Can Be Proud of Indonesia|Reza Aslan|November 10, 2010|DAILY BEAST
It was a decayed house of superb proportions, but of a fashion long passed away.
Checkmate|Joseph Sheridan Le Fanu
Some half-decayed pieces of cloth and portions of wearing apparel were still lying in it.
A Woman's Journey Round the World|Ida Pfeiffer
Lincoln Castle, much decayed and ruinous, is an appropriate feature of one of the public parks.
British Highways And Byways From A Motor Car|Thomas D. Murphy
Two miles from Winchelsea is Rye, another of the decayed seaports of the southeast coast.
British Highways And Byways From A Motor Car|Thomas D. Murphy
On an isolated mountain was situated the famous old fortress of Assergur, from which arose two half-decayed minarets.
A Woman's Journey Round the World|Ida Pfeiffer

British Dictionary definitions for decay

decay

/ (dɪˈkeɪ) /

verb

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

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

Also: disintegrate (intr) physics

(of an atomic nucleus) to undergo radioactive disintegration
(of an elementary particle) to transform into two or more different elementary particles

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

noun

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

the state brought about by this process

decomposition, as of vegetable matter

rotten or decayed matterthe dentist drilled out the decay

physics

See radioactive decay
a spontaneous transformation of an elementary particle into two or more different particles
of an excited atom or molecule, losing energy by the spontaneous emission of photons

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

music the fading away of a note

Derived forms of decay

decayable, adjective

Word Origin for decay

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

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for decay

decay

[ dĭ-kā′ ]

Noun

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

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. See more at fundamental force radioactive decay.

Verb

To undergo decay.

decay

OTHER WORDS FOR decay

Origin of decay

synonym study for decay

OTHER WORDS FROM decay

Words related to decay

How to use decay in a sentence

British Dictionary definitions for decay

Derived forms of decay

Word Origin for decay

Scientific definitions for decay