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Definitions

decay

[dih-key] / dɪˈkeɪ /
NOUN
breaking down, collapse
Synonyms
STRONGEST
blight corrosion decomposition degeneration deterioration disintegration disrepair extinction impairment rot
STRONG
adulteration atrophy caries consumption crumbling decadence decline decrease decrepitude degeneracy depreciation dilapidation dissolution downfall dying fading failing gangrene mortification perishing putrefaction putrescence putridity putridness rotting ruin ruination rust senescence spoilage spoilation wasting withering
WEAK
wasting away
Antonyms
STRONGEST
building development growth improvement
STRONG
ascent construction increase morality rise
WEAK
flourish germination ripening strength strengthening
VERB
deteriorate, crumble
Synonyms
STRONGEST
atrophy corrode decompose degenerate discolor disintegrate dissolve dwindle fade get worse lessen mortify pollute rot shrivel wane wither
STRONG
blight collapse curdle decline defile depreciate dry-rot fail mildew mold molder perish putrefy sap sicken sink slump spoil suppurate turn weaken
WEAK
be impaired become contaminated break up go bad go to seed go to the dogs hit rock bottom hit the skids pejorate putresce reach depths waste away wear away
Antonyms
STRONGEST
brighten build color combine develop enlarge expand extend grow improve increase put together raise strengthen unite
STRONG
ascend help make well prosper rise
WEAK
flourish germinate ripen

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The nonrenewable gas is produced by radioactive decay deep under the earth and escapes into space once released.

From The Wall Street Journal • Mar. 31, 2026

An option that doesn’t lose value to time decay has the appearance of increasing implied volatility.

From MarketWatch • Mar. 26, 2026

This motion strongly affected both the timing and the outcome of the decay.

From Science Daily • Mar. 24, 2026

An extended gradual decay also might sometimes allow for modestly positive news such as the data that garnered so much excitement this week.

From The Wall Street Journal • Mar. 19, 2026

But the stories she told them of moral decay, of the wicked who preyed on the good, were made more poignant by this clutch of arm to breast.

From "Jazz" by Toni Morrison

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.