Source : Webster's Revised Unabridged Dictionary (1913)

Decease \De*cease"\, v. i. [imp. & p. p. {Deceased}; p. pr. &
   vb. n. {Deceasing}.]
   To depart from this life; to die; to pass away.

         She's dead, deceased, she's dead.        --Shak.

         When our summers have deceased.          --Tennyson.

         Inasmuch as he carries the malignity and the lie with
         him, he so far deceases from nature.     --Emerson.

Deceased \De*ceased"\, a.
   Passed away; dead; gone.

   {The deceased}, the dead person.

Source : WordNet®

deceased
     adj : dead; "he is deceased"; "our dear departed friend" [syn: {asleep(p)},
            {at peace(p)}, {at rest(p)}, {departed}, {gone}]
     n : someone who is no longer alive; "I wonder what the dead
         person would have done" [syn: {dead person}, {dead soul},
          {deceased person}, {decedent}, {departed}]