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decay

From Wiktionary, the free dictionary

English

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The apple on the right shows signs of decay.

Etymology

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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.

Pronunciation

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Noun

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decay (usually uncountable, plural decays)

  1. (biology) 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
    • 1895, H. G. Wells, chapter X, in The Time Machine:
      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.
    • 1914, Robert Frost, The Wood-pile:
      He spent himself, the labour of his axe,
      And leave it there far from a useful fireplace
      To warm the frozen swamp as best it could
      With the slow smokeless burning of decay.
  2. 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
  3. (physics) Radioactive decay; decomposition of an atom or its nucleus.
    Synonym: nuclear decayatomic decay
    alpha decay—gamma decay—fission decaydecay chain
  4. (physics) Particle decay; decomposition of a sub-atomic particle.
  5. Continuous decrease of a quantity.
    exponential decaydecay rate—orbital decaydecay time—decay constant—time decay
  6. (obsolete) Overthrow, destruction, ruin, death.
    • 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; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire; London: Scolar Press, 1973, →ISBN, Act II, scene vi:
      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:
  7. (programming) Array decay.

Usage notes

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  • Historically, definition 1 could not include our modern theories of how such rot occurs. It was something that was restricted to animal and vegetable matter.

Derived terms

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Translations

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The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

Verb

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

  1. (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.
    1. (intransitive, electronics, of storage media or the data on them) To undergo bit rot, that is, gradual degradation.
    2. (intransitive, computing, of software) 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, physics, of a satellite's orbit) To undergo prolonged reduction in altitude (above the orbited body).
      • 2009, Francis Lyall, Paul B. Larsen, Space Law: A Treatise, page 120:
        Damaged on lift-off, Skylab was left in orbit until its orbit decayed.
  2. (intransitive, of organic material) To rot, to go bad.
    The cat's body decayed rapidly.
    • 1907, Henry John Elwes and Augustine Henry, The Trees of Great Britain & Ireland, Volume 2/Cladastris:
      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.
  3. (intransitive, transitive, physics, chemistry, of an unstable atom) To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons; to undergo radioactive decay.
    • 2005, Encyclopedia of Earth Science, edited by Timothy M. Kusky, →ISBN, page 349:
      Uranium decays to radium through a long series of steps with a cumulative half-life of 4.4 billion years.
  4. (intransitive, transitive, physics, of a quantum system) To undergo optical decay, that is, to relax to a less excited state, usually by emitting a photon or phonon.
  5. (intransitive, aviation) Loss of airspeed due to drag.
  6. (transitive) To cause to rot or deteriorate.
    The extreme humidity decayed the wooden sculptures in the museum's collection in a matter of years.
  7. (programming, intransitive) Of an array: to lose its type and dimensions and be reduced to a pointer, for example when passed to a function.

Synonyms

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Derived terms

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Translations

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The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

References

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Anagrams

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