Standard Lemma guide

decay

noun · verb · 25 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • UK: /dɪˈkeɪ/
  • rhymes with -eɪ
  • US: dē-kāʹ
  • US: /diˈkeɪ/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • CMU ARPABET: D IH0 K EY1 Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

Rot; any processes or result of organic matter being gradually decomposed, especially by microbial action.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

Topics: biology, natural-sciences

Examples

  • tooth decay/dental decay—wood-decay fungi—bacterial decay—photochemical decay

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

Deterioration of condition; loss of status, quality, strength, or fortune.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

Examples

  • civic and moral decay—systemic decay—fall into decay—urban decay—arrested decay—memory decay

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

Radioactive decay; decomposition of an atom or its nucleus.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

Topics: natural-sciences, physical-sciences, physics

Examples

  • alpha decay—gamma decay—fission decay—decay chain

Meaning relationships

Synonyms: nuclear decay—atomic decay

Antonyms: none provided

4

noun

Meaning 4

Particle decay; decomposition of a sub-atomic particle.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

5

noun

Meaning 5

Continuous decrease of a quantity.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

Examples

  • exponential decay—decay rate—orbital decay—decay time—decay constant—time decay

Meaning relationships

Synonyms: none provided

Antonyms: none provided

6

noun

Meaning 6

Overthrow, destruction, ruin, death.

Definition source: English Wiktionary via Wiktextract

Usage: obsolete, uncountable, usually

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

7

noun

Meaning 7

Array decay.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, programming, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

8

verb

Meaning 8

To deteriorate, to get worse, to lose strength or health, to decline in quality.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Examples

  • The pair loved to take pictures in the decaying hospital on forty-third street.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

9

verb

Meaning 9

To deteriorate, to get worse, to lose strength or health, to decline in quality.

To undergo bit rot, that is, gradual degradation.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Topics: business, electrical-engineering, electricity, electromagnetism, electronics, energy, engineering, natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

10

verb

Meaning 10

To deteriorate, to get worse, to lose strength or health, to decline in quality.

To undergo software rot, that is, to fail to be updated in a changing environment, so as to eventually become legacy or obsolete.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

11

verb

Meaning 11

To deteriorate, to get worse, to lose strength or health, to decline in quality.

To undergo prolonged reduction in altitude (above the orbited body).

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

12

verb

Meaning 12

To rot, to go bad.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Examples

  • The cat's body decayed rapidly.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

13

verb

Meaning 13

To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons; to undergo radioactive decay.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive, transitive

Topics: chemistry, natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

14

verb

Meaning 14

To undergo optical decay, that is, to relax to a less excited state, usually by emitting a photon or phonon.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive, transitive

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

15

verb

Meaning 15

Loss of airspeed due to drag.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Topics: aeronautics, aerospace, aviation, business, engineering, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

16

verb

Meaning 16

To cause to rot or deteriorate.

Definition source: English Wiktionary via Wiktextract

Usage: transitive

Examples

  • The extreme humidity decayed the wooden sculptures in the museum's collection in a matter of years.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

17

verb

Meaning 17

Of an array: to lose its type and dimensions and be reduced to a pointer, for example when passed to a function.

Definition source: English Wiktionary via Wiktextract

Usage: intransitive

Topics: computing, engineering, mathematics, natural-sciences, physical-sciences, programming, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

18

noun

Meaning 18

the organic phenomenon of rotting

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: decomposition

Antonyms: none provided

Broader terms: organic phenomenon

19

noun

Meaning 19

a gradual decrease; as of stored charge or current

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: decline

Antonyms: none provided

Broader terms: decrease, decrement

Narrower terms: exponential decay, exponential return

20

noun

Meaning 20

the process of gradually becoming inferior

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: natural process, natural action, action, activity

Narrower terms: cavity, caries, dental caries, tooth decay, corruption, decomposition, rot, rotting, putrefaction, dilapidation, ruin, spoilage, spoiling

21

noun

Meaning 21

the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: radioactive decay, disintegration

Antonyms: none provided

Broader terms: nuclear reaction

Narrower terms: alpha decay, beta decay

22

noun

Meaning 22

an inferior state resulting from the process of decaying

Definition source: Princeton WordNet 3.0

Examples

  • the corpse was in an advanced state of decay
  • the house had fallen into a serious state of decay and disrepair

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: unsoundness

Narrower terms: putrefaction, rot, decomposition, disintegration, deterioration, impairment, rancidity

23

verb

Meaning 23

fall into decay or ruin

Definition source: Princeton WordNet 3.0

Examples

  • The unoccupied house started to decay

Meaning relationships

Synonyms: crumble, dilapidate

Antonyms: none provided

Broader terms: change

Narrower terms: deteriorate, corrode, rust, weather, erode, gnaw, gnaw at, eat at, wear away, wilt, droop, ruin, break, wear, wear out, bust, fall apart

24

verb

Meaning 24

lose a stored charge, magnetic flux, or current

Definition source: Princeton WordNet 3.0

Examples

  • the particles disintegrated during the nuclear fission process

Meaning relationships

Synonyms: disintegrate, decompose

Antonyms: none provided

Broader terms: change integrity

25

verb

Meaning 25

undergo decay or decomposition

Definition source: Princeton WordNet 3.0

Examples

  • The body started to decay and needed to be cremated

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: change

Narrower terms: decompose, rot, molder, moulder, spoil, go bad, putrefy, deliquesce

History

Etymology

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.

Across languages

Translations

157 source translations are retained for this English entry.

  • Arabic: نَخْر (naḵr) — process or result of being gradually decomposed
  • Bulgarian: разлагане (razlagane) — process or result of being gradually decomposed
  • Catalan: descomposició — process or result of being gradually decomposed
  • Catalan: desintegració — process or result of being gradually decomposed
  • Czech: rozklad — process or result of being gradually decomposed
  • Czech: hniloba — process or result of being gradually decomposed
  • Danish: nedbrydning — process or result of being gradually decomposed
  • Danish: forfald — process or result of being gradually decomposed
  • Dutch: verval — process or result of being gradually decomposed
  • Finnish: lahoaminen — process or result of being gradually decomposed
  • Finnish: laho — process or result of being gradually decomposed
  • French: décrépitude — process or result of being gradually decomposed
  • Galician: deterioración — process or result of being gradually decomposed
  • Galician: apodrecemento — process or result of being gradually decomposed
  • Galician: putrefacción — process or result of being gradually decomposed
  • German: Verfall — process or result of being gradually decomposed
  • German: Verwesung — process or result of being gradually decomposed
  • German: Fäulnis — process or result of being gradually decomposed
  • Greek: σήψη (sípsi) — process or result of being gradually decomposed
  • Ancient Greek: σῆψις (sêpsis) — process or result of being gradually decomposed
  • Hebrew: דעיכה (de'ichá) — process or result of being gradually decomposed
  • Hindi: अपघटन (apaghṭan) — process or result of being gradually decomposed
  • Hungarian: bomlás — process or result of being gradually decomposed
  • Ido: dekado — process or result of being gradually decomposed
  • Indonesian: pelapukan — process or result of being gradually decomposed
  • Indonesian: peluruhan — process or result of being gradually decomposed
  • Irish: meath — process or result of being gradually decomposed
  • Japanese: 腐敗 (fuhai) — process or result of being gradually decomposed
  • Korean: 부패 (bupae) — process or result of being gradually decomposed
  • Latin: cariēs — process or result of being gradually decomposed
  • Latin: tābēs — process or result of being gradually decomposed
  • Low German: Fuulnis — process or result of being gradually decomposed
  • Macedonian: распа́ѓање (raspáǵanje) — process or result of being gradually decomposed
  • Macedonian: ра́спад (ráspad) — process or result of being gradually decomposed
  • Malay: kerosakan — process or result of being gradually decomposed
  • Malay: pereputan — process or result of being gradually decomposed
  • Malayalam: ജീർണ്ണിക്കൽ (jīṟṇṇikkal) — process or result of being gradually decomposed
  • Māori: hanehane — process or result of being gradually decomposed
  • Māori: popo — process or result of being gradually decomposed
  • Norwegian Bokmål: nedbryting — process or result of being gradually decomposed
  • Old English: þreax — process or result of being gradually decomposed
  • Persian: تباهی (tabâhi) — process or result of being gradually decomposed
  • Persian: واپاشی (vâpâši) — process or result of being gradually decomposed
  • Polish: rozkład — process or result of being gradually decomposed
  • Portuguese: deterioração — process or result of being gradually decomposed
  • Portuguese: apodrecimento — process or result of being gradually decomposed
  • Portuguese: putrefação — process or result of being gradually decomposed
  • Portuguese: decomposição — process or result of being gradually decomposed
  • Romanian: descompunere — process or result of being gradually decomposed
  • Russian: разложе́ние (razložénije) — process or result of being gradually decomposed
  • Russian: распа́д (raspád) — process or result of being gradually decomposed
  • Russian: гние́ние (gnijénije) — process or result of being gradually decomposed
  • Sanskrit: क्षय (kṣaya) — process or result of being gradually decomposed
  • Scottish Gaelic: crìonadh — process or result of being gradually decomposed
  • Scottish Gaelic: mùthadh — process or result of being gradually decomposed
  • Serbo-Croatian: raspad — process or result of being gradually decomposed
  • Spanish: descomposición — process or result of being gradually decomposed
  • Spanish: deterioración — process or result of being gradually decomposed
  • Spanish: putrefacción — process or result of being gradually decomposed
  • Spanish: podredumbre — process or result of being gradually decomposed
  • Spanish: decaimiento — process or result of being gradually decomposed
  • Swedish: förruttnelse — process or result of being gradually decomposed
  • Swedish: sönderfall — process or result of being gradually decomposed
  • Swedish: förfall — process or result of being gradually decomposed
  • Tagalog: pugnaw — process or result of being gradually decomposed
  • Ukrainian: розпад (rozpad) — process or result of being gradually decomposed
  • Ukrainian: розпадання (rozpadannja) — process or result of being gradually decomposed
  • Ukrainian: розклад (rozklad) — process or result of being gradually decomposed
  • Ukrainian: розклада́ння (rozkladánnja) — process or result of being gradually decomposed
  • Ukrainian: розлож (rozlož) — process or result of being gradually decomposed
  • Ukrainian: розложення (rozložennja) — process or result of being gradually decomposed
  • Bulgarian: влошаване (vlošavane) — deterioration of condition
  • Catalan: deteriorament — deterioration of condition
  • Catalan: decadència — deterioration of condition
  • Czech: rozklad — deterioration of condition
  • Danish: forfald — deterioration of condition
  • Danish: svækkelse — deterioration of condition
  • Finnish: heikkeneminen — deterioration of condition
  • Finnish: rapautuminen — deterioration of condition
  • Galician: decadencia — deterioration of condition
  • Galician: deterioración — deterioration of condition
  • Hungarian: romlás — deterioration of condition
  • Hungarian: hanyatlás — deterioration of condition
  • Hungarian: pusztulás — deterioration of condition
  • Indonesian: pelapukan — deterioration of condition
  • Indonesian: peluruhan — deterioration of condition
  • Indonesian: kemerosotan — deterioration of condition
  • Irish: meath — deterioration of condition
  • Irish: meathlú — deterioration of condition
  • Korean: 쇠약 (soeyak) — deterioration of condition
  • Macedonian: влошу́вање (vlošúvanje) — deterioration of condition
  • Malay: susutan — deterioration of condition
  • Malayalam: ജീർണ്ണിക്കൽ (jīṟṇṇikkal) — deterioration of condition
  • Polish: rozkład — deterioration of condition
  • Polish: degradacja — deterioration of condition
  • Romanian: decădere — deterioration of condition
  • Russian: упа́док (upádok) — deterioration of condition
  • Russian: спад (spad) — deterioration of condition
  • Spanish: deterioración — deterioration of condition
  • Spanish: desintegración — deterioration of condition
  • Spanish: decadencia — deterioration of condition
  • Spanish: decaimiento — deterioration of condition
  • Spanish: descaecimiento — deterioration of condition
  • Ottoman Turkish: خراب (harab) — deterioration of condition
  • Arabic: اضمحل — to deteriorate
  • Arabic: تضعضع — to deteriorate
  • Armenian: փչանալ (pʻčʻanal) — to deteriorate
  • Bulgarian: разлагам се (razlagam se) — to deteriorate
  • Bulgarian: развалям се (razvaljam se) — to deteriorate
  • Catalan: deteriorar-se — to deteriorate
  • Catalan: fer-se malbé — to deteriorate
  • Czech: rozkládat se — to deteriorate
  • Danish: brydes ned — to deteriorate
  • Danish: nedbrydes — to deteriorate
  • Danish: forfalde — to deteriorate
  • Danish: henfalde — to deteriorate
  • Dutch: vervallen — to deteriorate
  • Dutch: in verval raken — to deteriorate
  • Dutch: verloederen — to deteriorate
  • Esperanto: kadukiĝi — to deteriorate
  • Finnish: heikentyä — to deteriorate
  • Finnish: rapautua — to deteriorate
  • Finnish: rappeutua — to deteriorate
  • Finnish: heiketä — to deteriorate
  • French: pourrir — to deteriorate
  • Georgian: ფუჭდება (puč̣deba) — to deteriorate
  • German: verfallen — to deteriorate
  • German: verderben — to deteriorate
  • Hungarian: elpusztul — to deteriorate
  • Hungarian: tönkremegy — to deteriorate
  • Irish: meath — to deteriorate
  • Irish: meathlaigh — to deteriorate
  • Korean: 부패하다 (bupaehada) — to deteriorate
  • Malayalam: ജീർണ്ണിക്കുക (jīṟṇṇikkuka) — to deteriorate
  • Māori: taimate — to deteriorate
  • Māori: koropungapunga — to deteriorate
  • Persian: تباهیدن (tabâhidan) — to deteriorate
  • Persian: واپاشیدن (vâpâšidan) — to deteriorate
  • Portuguese: decompor-se — to deteriorate
  • Portuguese: deteriorar — to deteriorate
  • Romanian: descompune — to deteriorate
  • Russian: по́ртиться (pórtitʹsja) — to deteriorate
  • Russian: ухудша́ться (uxudšátʹsja) — to deteriorate
  • Spanish: decaer — to deteriorate
  • Spanish: periclitar — to deteriorate
  • Spanish: descaecer — to deteriorate
  • Swedish: mattas — to deteriorate
  • Swedish: försämras — to deteriorate
  • Swedish: förfalla — to deteriorate
  • Swedish: tackla av — to deteriorate
  • Turkish: fenalaşmak — to deteriorate
  • Catalan: desintegrar-se — To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons.
  • French: se désintégrer — To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons.
  • Russian: распада́ться (raspadátʹsja) — To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons.
  • Russian: распа́сться (raspástʹsja) — To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons.
  • Ukrainian: розпада́тися (rozpadátysja) — To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons.
  • Ukrainian: розпа́стися (rozpástysja) — To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons.
Real reading context

decay in complete knowledge articles