# decay

> English word · Noun · IPA /dɪˈkeɪ/ · frequency rank #9,160

## Definitions
1. Rot; any processes or result of organic matter being gradually decomposed, especially by microbial action.
2. Deterioration of condition; loss of status, quality, strength, or fortune.
3. Radioactive decay; decomposition of an atom or its nucleus.
4. Particle decay; decomposition of a sub-atomic particle.
5. Continuous decrease of a quantity.
6. Overthrow, destruction, ruin, death.
7. Array decay.

## Etymology
From Middle English decayen, dekeyen (“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 away, fail, sink, perish”), from de (“down”) + cadere (“to fall”). Compare decadent and decadence.

## Easily confused with
- **dey** (https://plainspell.com/en/vs/decay-vs-dey)
- **deck** (https://plainspell.com/en/vs/decay-vs-deck)
- **deny** (https://plainspell.com/en/vs/decay-vs-deny)
- **defy** (https://plainspell.com/en/vs/decay-vs-defy)
- **deco** (https://plainspell.com/en/vs/decay-vs-deco)
- **deva** (https://plainspell.com/en/vs/decay-vs-deva)
- **DMCA** (https://plainspell.com/en/vs/decay-vs-dmca)
- **dewy** (https://plainspell.com/en/vs/decay-vs-dewy)
- **delay** (https://plainspell.com/en/vs/decay-vs-delay)
- **derby** (https://plainspell.com/en/vs/decay-vs-derby)
- **decor** (https://plainspell.com/en/vs/decay-vs-decor)
- **decks** (https://plainspell.com/en/vs/decay-vs-decks)
- **deity** (https://plainspell.com/en/vs/decay-vs-deity)
- **Dewey** (https://plainspell.com/en/vs/decay-vs-dewey)
- **Derry** (https://plainspell.com/en/vs/decay-vs-derry)
- **decoy** (https://plainspell.com/en/vs/decay-vs-decoy)
- **duchy** (https://plainspell.com/en/vs/decay-vs-duchy)
- **Desai** (https://plainspell.com/en/vs/decay-vs-desai)
- **Dicky** (https://plainspell.com/en/vs/decay-vs-dicky)
- **Dewar** (https://plainspell.com/en/vs/decay-vs-dewar)

## Common misspellings (7)
`dceay`, `ddecay`, `deacy`, `decayy`, `deccay`, `decya`, `edcay`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/decay