The Collaborative International Dictionary of English v.0.48:

Decay \De*cay"\, v. t.
   1. To cause to decay; to impair. [R.]
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            Infirmity, that decays the wise.      --Shak.
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   2. To destroy. [Obs.] --Shak.
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The Collaborative International Dictionary of English v.0.48:

Decay \De*cay"\, n.
   1. 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.
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            Perhaps my God, though he be far before,
            May turn, and take me by the hand, and more
            May strengthen my decays.             --Herbert.
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            His [Johnson's] failure was not to be ascribed to
            intellectual decay.                   --Macaulay.
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            Which has caused the decay of the consonants to
            follow somewhat different laws.       --James Byrne.
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   2. Destruction; death. [Obs.] --Spenser.
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   3. Cause of decay. [R.]
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            He that plots to be the only figure among ciphers,
            is the decay of the whole age.        --Bacon.

   Syn: Decline; consumption. See Decline.
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The Collaborative International Dictionary of English v.0.48:

Decay \De*cay"\, v. i. [imp. & p. p. Decayed; p. pr. & vb. n.
   Decaying.] [OF. decaeir, dechaer, decheoir, F. d['e]choir,
   to decline, fall, become less; L. de- + cadere to fall. See
   Chance.]
   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.
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         Ill fares the land, to hastening ills a prey,
         Where wealth accumulates and men decay.  --Goldsmith.
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