Definitions for Decaydɪˈkeɪ

Random House Webster's College Dictionary

de•cay^*dɪˈkeɪ(v.i.)

to become decomposed; rot.
Category: Microbiology
to decline in health, prosperity, etc.; deteriorate.
(of an atomic nucleus) to undergo radioactive disintegration.
Category: Physics
(v.t.)to cause to decompose; rot.
Category: Microbiology
(n.)decomposition; rot.
Category: Microbiology
a gradual and progressive decline.
the spontaneous radioactive transformation of a nucleus or particle into one or more different nuclei or particles.
Category: Physics
progressive change in the path of an earth-orbiting satellite due to atmospheric drag.
Category: Aerospace

^* Syn: decay , decompose , disintegrate , rot imply a deterioration or falling away from a sound condition. decay implies either entire or partial deterioration by progressive natural changes: Teeth decay.decompose suggests the reducing of a substance to its component elements: Moisture makes some chemical compounds decompose.disintegrate emphasizes the breaking up, going to pieces, or wearing away of anything, so that its original wholeness is impaired: Rocks disintegrate.rot is applied esp. to decaying vegetable matter, which may or may not emit offensive odors: Potatoes rot.

Origin of decay:

1425–75; < ONF decair=de-de - +cair to fall 蠐 L cadere

de•cay′less(adj.)

Princeton's WordNet

decay(noun)
the process of gradually becoming inferior
decay, decline(noun)
a gradual decrease; as of stored charge or current
decay, decomposition(noun)
the organic phenomenon of rotting
decay(noun)
an inferior state resulting from the process of decaying
"the corpse was in an advanced state of decay"; "the house had fallen into a serious state of decay and disrepair"
decay, radioactive decay, disintegration(verb)
the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation
disintegrate, decay, decompose(verb)
lose a stored charge, magnetic flux, or current
"the particles disintegrated during the nuclear fission process"
decay, crumble, dilapidate(verb)
fall into decay or ruin
"The unoccupied house started to decay"
decay(verb)
undergo decay or decomposition
"The body started to decay and needed to be cremated"

Kernerman English Learner's Dictionary

decay(verb)ɪˈkeɪ
to break down or cause to break down by natural processes; = rot
as the body decays; Sugar decays your teeth.
decayɪˈkeɪ
to become gradually worse
neighborhoods decaying as the years pass; to watch standards decay.

Wiktionary

decay(Noun)
The process or result of being gradually decomposed.
decay(Noun)
A deterioration of condition.
decay(Verb)
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.
decay(Verb)
To rot, to go bad.
The cat's body decayed rapidly.
decay(Verb)
To change by undergoing fission, by emitting radiation, or by capturing or losing one or more electrons.
decay(Verb)
To undergo optical decay, that is, to relax to a less excited state, usually by emitting a photon or phonon.
decay(Verb)
To cause to rot or deteriorate.
The extreme humidity decayed the wooden sculptures in the museum's collection in a matter of years.

Origin: From decair, from *, restored form of decidere, from de + cadere; compare decadent and decadence.

Webster Dictionary

Decay(verb)
to pass gradually from a sound, prosperous, or perfect state, to one of imperfection, adversity, or dissolution; to waste away; to decline; to fail; to become weak, corrupt, or disintegrated; to rot; to perish; as, a tree decays; fortunes decay; hopes decay
Decay(verb)
to cause to decay; to impair
Decay(verb)
to destroy
Decay(noun)
gradual failure of health, strength, soundness, prosperity, or of any species of excellence or perfection; tendency toward dissolution or extinction; corruption; rottenness; decline; deterioration; as, the decay of the body; the decay of virtue; the decay of the Roman empire; a castle in decay
Decay(noun)
destruction; death
Decay(noun)
cause of decay

The New Hacker's Dictionary

decay
[from nuclear physics] An automatic conversion which is applied to most array-valued expressions in C; they ‘decay into’ pointer-valued expressions pointing to the array's first element. This term is borderline techspeak, but is not used in the official standard for the language.