Definition of "Decay" :

noun: the organic phenomenon of rotting

noun: a gradual decrease; as of stored charge or current

noun: the process of gradually becoming inferior

noun: the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation

noun: an inferior state resulting from the process of decaying

"The corpse was in an advanced state of decay."

verb: fall into decay or ruin

"The unoccupied house started to decay."

verb: lose a stored charge, magnetic flux, or current

verb: undergo decay or decomposition

"The body started to decay and needed to be cremated."