- to become decomposed; rot: vegetation that was decaying.
- to decline in excellence, prosperity, health, etc.; deteriorate.
- (of a radioactive nucleus) to change spontaneously into one or more different nuclei in a process in which atomic particles, as alpha particles, are emitted from the nucleus, electrons are captured or lost, or fission takes place.
- to cause to decay or decompose; rot: The dampness of the climate decayed the books.
- decomposition; rot: Decay made the wood unsuitable for use.
- a gradual falling into an inferior condition; progressive decline: the decay of international relations; the decay of the Aztec civilizations.
- decline in or loss of strength, health, intellect, etc.: His mental decay is distressing.
- radioactive decay.
- the progressive, accelerating reduction in orbital parameters, particularly apogee and perigee, of a spacecraft due to atmospheric drag.
- to decline or cause to decline gradually in health, prosperity, excellence, etc; deteriorate; waste away
- to rot or cause to rot as a result of bacterial, fungal, or chemical action; decompose
- Also: disintegrate (intr) physics
- (of an atomic nucleus) to undergo radioactive disintegration
- (of an elementary particle) to transform into two or more different elementary particles
- (of a stored charge, magnetic flux, etc) to decrease gradually when the source of energy has been removed
- the process of decline, as in health, mentality, beauty, etc
- the state brought about by this process
- decomposition, as of vegetable matter
- rotten or decayed matter
- physics
- See radioactive decay
- a spontaneous transformation of an elementary particle into two or more different particles
- of an excited atom or molecule, losing energy by the spontaneous emission of photons
- a gradual decrease of a stored charge, magnetic flux, current, etc, when the source of energy has been removed
- the fading away of a note
