/dɪˈkeɪ/, /diˈkeɪ/
OriginFrom 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.
- uncountable, usuallyRot; 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 ”
“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.”
- uncountable, usuallyDeterioration of condition; loss of status, quality, strength, or fortune.
“Although the best room of the inn, it had the melancholy aspect of grandeur in decay, and was much too vast for comfort.”
“civic and moral decay—systemic decay—fall into decay—urban decay—arrested decay—memory decay”
- uncountable, usuallyRadioactive decay; decomposition of an atom or its nucleus.
“alpha decay—gamma decay—fission decay—decay chain”
- uncountable, usuallyParticle decay; decomposition of a sub-atomic particle.
- uncountable, usuallyContinuous decrease of a quantity.
“exponential decay—decay rate—orbital decay—decay time—decay constant—time decay”
- obsolete, uncountable, usuallyOverthrow, 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 fr”
- uncountable, usuallyArray decay.
- intransitiveTo 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.”
- intransitiveTo undergo bit rot, that is, gradual degradation.
- intransitiveTo undergo software rot, that is, to fail to be updated in a changing environment, so as to eventually become legacy or obsolete.
- intransitiveTo undergo prolonged reduction in altitude (above the orbited body).
“Damaged on lift-off, Skylab was left in orbit until its orbit decayed.”
- intransitiveTo 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.”
- intransitive, transitiveTo 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.”
- intransitive, transitiveTo undergo optical decay, that is, to relax to a less excited state, usually by emitting a photon or phonon.
- intransitiveLoss of airspeed due to drag.
- transitiveTo 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.”
- intransitiveOf an array: to lose its type and dimensions and be reduced to a pointer, for example when passed to a function.
Formsdecays(plural) · decays(present, singular, third-person) · decaying(participle, present) · decayed(participle, past) · decayed(past)