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."