decay

Syllables: de·cay/dɪˈkeɪ/US/diˈkeɪ/

decay noun: rot; any processes or result of organic matter being gradually decomposed, especially by microbial action.

Image: Evelyn Simak, CC BY-SA 2.0, via Wikimedia Commons

Noun

decay (usually uncountable, plural decays)

(usually) Rot; any processes or result of organic matter being gradually decomposed, especially by microbial action.
- tooth decay/dental decay—wood-decay fungi—bacterial decay—photochemical decay
- I fancied at first the stuff was paraffin wax, and smashed the jar accordingly. But the odor of camphor was unmistakable. It struck me as singularly odd, that among the universal decay, this volatile substance had chanced to survive, perhaps through many thousand years.1895, H. G. Wells, chapter X, in The Time Machine
(usually) Deterioration of condition; loss of status, quality, strength, or fortune.
- civic and moral decay—systemic decay—fall into decay—urban decay—arrested decay—memory decay
- Although the best room of the inn, it had the melancholy aspect of grandeur in decay, and was much too vast for comfort.1841 February–November, Charles Dickens, “Barnaby Rudge. Chapter 10.”, in Master Humphrey’s Clock, volume II, London: Chapman & Hall, […], →OCLC
(usually) Radioactive decay; decomposition of an atom or its nucleus.
- alpha decay—gamma decay—fission decay—decay chain
Synonyms:

nuclear decay—atomic decay
(usually) Particle decay; decomposition of a sub-atomic particle.
(usually) Continuous decrease of a quantity.
- exponential decay—decay rate—orbital decay—decay time—decay constant—time decay
(obsolete, usually) Overthrow, destruction, ruin, death.
- Let’s cheere our ſouldiers to incounter him,
  That grieuous image of ingratitude:
  That fiery thirſter after Soueraigntie: […]
  Reſolue my Lords and louing ſouldiers now,
  To ſaue your king and country from decay:c. 1587–1588 (date written), [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], 2nd edition, part 1, London: […] [R. Robinson for] Richard Iones, […], published 1592, →OCLC...
(usually) Array decay.

Verb

decay (third-person singular simple present decays, present participle decaying, simple past and past participle decayed)

(intransitive) To deteriorate, to get worse, to lose strength or health, to decline in quality.
- The pair loved to take pictures in the decaying hospital on forty-third street.
- "The signalling at Salisbury has be replaced for safety reasons in the next handful of years. It's worn out. Last week, there was a signal cable issue near Tisbury that stopped proper running for four whole days. The system is decaying.2026 February 18, Paul Clifton, “West of England Line problems laid bare”, in RAIL, number 1055, page 7
1. (intransitive) To undergo bit rot, that is, gradual degradation.
2. (intransitive) To undergo software rot, that is, to fail to be updated in a changing environment, so as to eventually become legacy or obsolete.
3. (intransitive) To undergo prolonged reduction in altitude (above the orbited body).
  - Damaged on lift-off, Skylab was left in orbit until its orbit decayed.2009, Francis Lyall, Paul B. Larsen, Space Law: A Treatise, page 120
(intransitive) To rot, to go bad.
- The cat's body decayed rapidly.
- The largest tree known to us is at Syon (Plate 124), which in 1904 was no less than 60 feet in height by 7 feet in girth and still a fine tree, though its trunk is decaying inside.1907, Henry John Elwes and Augustine Henry, The Trees of Great Britain & Ireland, Volume 2/Cladastris
(intransitive, transitive) To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons; to undergo radioactive decay.
- Uranium decays to radium through a long series of steps with a cumulative half-life of 4.4 billion years.2005, Encyclopedia of Earth Science, edited by Timothy M. Kusky, →ISBN, page 349
(intransitive, transitive) To undergo optical decay, that is, to relax to a less excited state, usually by emitting a photon or phonon.
(intransitive) Loss of airspeed due to drag.
(transitive) To cause to rot or deteriorate.
- The extreme humidity decayed the wooden sculptures in the museum's collection in a matter of years.
- Infirmity, that decays the wise.c. 1601–1602 (date written), William Shakespeare, “Twelfe Night, or What You Will”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and...
(intransitive) Of an array: to lose its type and dimensions and be reduced to a pointer, for example when passed to a function.

decay meaning in Hindi, Tamil, Urdu and Bengali

decay in Hindi

process or result of being gradually decomposed: अपघटन apaghṭan

decay in Tamil

அழுகுதல், தேய்தல், சிதைவு, சொத்தை, பல் சிதைவு

decay in Urdu

decay, loss, ruin: اتلاف itlāf
decay: کشی kaśī, خزاں xizā̃

decay in Bengali

ক্ষয় হওয়া, পচে যাওয়া

More languagesFewer languages

decay in Telugu: పుచ్చు puccu, పుప్పి puppi
decay in Malayalam: ജീർണ്ണിക്കൽ jīṟṇṇikkal, ജീർണ്ണിക്കുക jīṟṇṇikkuka
decay in Kannada: ಕ್ಷಯ kṣaya
decay in Punjabi: ਸੜਨ saṛan, ਸੜਨਾ saṛnā, سڑنا saṛnā, ਜ਼ਵਾਲ zavāl
decay in Gujarati: ક્ષય kṣaya, બળક્ષય baḷkṣaya
decay in Odia: ଧ୍ୱଂସ dhwaṁsa, ନଷ୍ଟ naṣṭa
decay in Sanskrit: क्षय kṣaya
decay in Nepali: क्षय
decay in Tagalog: pugnaw
decay in Arabic: نَخْر naḵr, اضمحل, تضعضع
decay in Malay: kerosakan, pereputan, susutan
decay in Indonesian: pelapukan, peluruhan, kemerosotan
decay in Persian: تباهی tabâhi, واپاشی vâpâši, تباهیدن tabâhidan, واپاشیدن vâpâšidan

Examples of decay in a sentence

The dentist pulled out the decayed tooth and put in a bridge.
This radioactive decay produces a hassium that lasts for several seconds.
Historians argue about when the Roman Empire began to peak and ultimately decay.

All 40 example sentences with decay

Synonyms of decay

nuclear decay—atomic decay
fester

Forms of decay

Noun
plural	decays
Verb
third-person singular present	decays
present participle	decaying
past participle	decayed
past	decayed

Past tense of decay: decayed

Plural of decay: decays

Origin of decay

From Middle English decaien (“to decrease, diminish”) and decai (“deterioration, decline in value”), from Anglo-Norman decaeir (“to fall away, decay, decline”), from Vulgar Latin *dēcadere, etymologically restored form of Latin dēcidere (“to fall down, to fail, sink or perish”), from de- (“of, from, away, down”) + cadere (“to fall”). Compare decadent and decadence.

Words formed from decay

Phrases with decay

Words that rhyme with decay

48 more rhymesFewer rhymes

Questions about decay

What does decay mean?: Decay means rot; any processes or result of organic matter being gradually decomposed, especially by microbial action.
What is decay in Hindi?: Decay in Hindi is अपघटन (apaghṭan). See Decay meaning in Hindi.
What part of speech is decay?: Decay can be a noun or a verb.
How do you pronounce decay?: Decay is pronounced /dɪˈkeɪ/ (UK).
What is the plural of decay?: The plural of decay is decays.

Words near decay in the dictionary

Last updated: 2026-09-02

Pronunciation audio from Wikimedia Commons, each file under its own free license: LL-Q1860 (eng)-Vealhurl-decay.wav.

Cite this entry: “decay.” Word.ws, https://word.ws/decay. Based on Wiktionary, CC BY-SA 4.0.