Etymograph

English

decay

Decay comes from Anglo-Norman decaeir ‘to fall away, decay, decline’, and goes back to Proto-Indo-European *ḱad-.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*ḱad-1‘to fall’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*ḱádeti1reconstructed
  3. Proto-Italicc. 1500–700 BCE*kadō1‘to fall, sink’reconstructed
  4. Latinc. 75 BCE–200 CEcadō1‘to fall’
  5. Latinc. 75 BCE–200 CEdēcidō2as dēcidere, etymologically restored form‘to fall down, to fail, sink or perish’
  6. Vulgar Latinc. 100–700 CE*dēcadere2reconstructed
  7. Anglo-Normanc. 1066–1400decaeir2‘to fall away, decay, decline’
  8. Middle Englishc. 1150–1500decaien2‘to decrease, diminish’
  9. Englishearliest quotation c. 1587–1588decay2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin decido
  2. 2 Wiktionary, English decay
  3. Earliest quotation in Wiktionary’s entry: c. 1587–1588, Christopher Marlowe, Tamburlaine the Great. […] The First Part […]: “Let’s cheere our ſouldiers to incounter him, That grieuous…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*ḱad-Wiktionary, Latin decido‘to fall’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*ḱádetiWiktionary, Latin decidoreconstructed
  3. Proto-Italicc. 1500–700 BCE*kadōWiktionary, Latin decido‘to fall, sink’reconstructed
  4. Latinc. 75 BCE–200 CEcadōWiktionary, Latin decido‘to fall’
  5. Latinc. 75 BCE–200 CEdēcidōWiktionary, English decayas dēcidere, etymologically restored form‘to fall down, to fail, sink or perish’
  6. Vulgar Latinc. 100–700 CE*dēcadereWiktionary, English decayreconstructed
  7. Anglo-Normanc. 1066–1400decaeirWiktionary, English decay‘to fall away, decay, decline’
  8. Middle Englishc. 1150–1500decaienWiktionary, English decay‘to decrease, diminish’
  9. Englishearliest quotation c. 1587–1588decayWiktionary, English decay. Earliest quotation in Wiktionary’s entry: c. 1587–1588, Christopher Marlowe, Tamburlaine the Great. […] The First Part […]: “Let’s cheere our ſouldiers to incounter him, That grieuous…”

Linked words

through Latin cadō ‘to fall’

chance, case, accident, incident, occasion, cheat, incidence, casualty, coincide, occidental, cadence, recidivism, cadaver, occident, 15 more

through Latin dēcidō ‘to fall down, to fail, sink or perish’

decision, decide, deciduous, decadent, 2 more

Today it means

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

Sources

Sources: Wiktionary, “decay”; the older steps come from the Wiktionary entry for Latin decido. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *ḱad- / decay

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