What is the meaning of decay?

noun

• The process of gradually becoming inferior.
• A gradual decrease; as of stored charge or current.
  • synonyms: decline
• The organic phenomenon of rotting.
  • synonyms: decomposition
• An inferior state resulting from the process of decaying.
  • usage: "the corpse was in an advanced state of decay"; "the house had fallen into a serious state of decay and disrepair"
• The spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation.
  • synonyms: radioactive decay, disintegration

verb

• Lose a stored charge, magnetic flux, or current.
  • usage: "the particles disintegrated during the nuclear fission process"
  • synonyms: disintegrate, decompose
• Fall into decay or ruin.
  • usage: "The unoccupied house started to decay"
  • synonyms: crumble, dilapidate
• Undergo decay or decomposition.
  • usage: "The body started to decay and needed to be cremated"