The Collaborative International Dictionary of English v.0.48:

departed \departed\ adj.
   1. past; -- used of time; as, departed summers.

   Syn: bygone, bypast, foregone, gone.
        [WordNet 1.5 +PJC]

   2. dead; as, our dear departed parents. [euphemistic]

   Syn: asleep(predicate), at peace(predicate), at
        rest(predicate), cold, deceased, gone.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Depart \De*part"\, v. i. [imp. & p. p. Departed; p. pr. & vb.
   n. Departing.] [OE. departen to divide, part, depart, F.
   d['e]partir to divide, distribute, se d['e]partir to separate
   one's self, depart; pref. d['e]- (L. de) + partir to part,
   depart, fr. L. partire, partiri, to divide, fr. pars part.
   See Part.]
   1. To part; to divide; to separate. [Obs.] --Shak.
      [1913 Webster]

   2. To go forth or away; to quit, leave, or separate, as from
      a place or a person; to withdraw; -- opposed to arrive; --
      often with from before the place, person, or thing left,
      and for or to before the destination.
      [1913 Webster]

            I will depart to mine own land.       --Num. x. 30.
      [1913 Webster]

            Ere thou from hence depart.           --Milton.
      [1913 Webster]

            He which hath no stomach to this fight,
            Let him depart.                       --Shak.
      [1913 Webster]

   3. To forsake; to abandon; to desist or deviate (from); not
      to adhere to; -- with from; as, we can not depart from our
      rules; to depart from a title or defense in legal
      pleading.
      [1913 Webster]

            If the plan of the convention be found to depart
            from republican principles.           --Madison.
      [1913 Webster]

   4. To pass away; to perish.
      [1913 Webster]

            The glory is departed from Israel.    --1 Sam. iv.
                                                  21.
      [1913 Webster]

   5. To quit this world; to die.
      [1913 Webster]

            Lord, now lettest thou thy servant depart in peace.
                                                  --Luke ii. 29.
      [1913 Webster]

   To depart with, to resign; to part with. [Obs.] --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

departed \departed\ n. sing. & pl.
   someone who is no longer alive; as, let us pray for the
   departed.

   Syn: dead person, dead soul, deceased person, deceased,
        decedent.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

departed
    adj 1: well in the past; former; "bygone days"; "dreams of
           foregone times"; "sweet memories of gone summers";
           "relics of a departed era" [syn: bygone, bypast,
           departed, foregone, gone]
    2: dead; "he is deceased"; "our dear departed friend" [syn:
       asleep(p), at peace(p), at rest(p), deceased,
       departed, gone]
    n 1: someone who is no longer alive; "I wonder what the dead
         person would have done" [syn: dead person, dead soul,
         deceased person, deceased, decedent, departed]

Moby Thesaurus II by Grady Ward, 1.0:

127 Moby Thesaurus words for "departed":
   absconded, absent, ago, antiquated, antique, ashes, asleep,
   asleep in Jesus, at rest, away, bereft of life, blown over, body,
   bones, breathless, by, bygone, bypast, cadaver, called home,
   carcass, carrion, clay, cold, corpse, corpus delicti, croaked,
   crowbait, dated, dead, dead and buried, dead and gone, dead body,
   dead man, dead person, death-struck, deceased, decedent, defunct,
   deleted, demised, departed this life, destitute of life,
   disappeared, done for, dry bones, dust, earth, elapsed,
   embalmed corpse, exanimate, expired, extinct, fallen, finished,
   food for worms, forgotten, gone, gone away, gone glimmering,
   gone off, gone to glory, gone west, gone-by, has-been, inanimate,
   irrecoverable, lacking, lapsed, late, late lamented,
   launched into eternity, left, lifeless, lost, martyred, missing,
   mortal remains, mummification, mummy, no longer present, no more,
   nonattendant, nonexistent, not found, not present, obsolete,
   omitted, organic remains, out of sight, over, passe, passed,
   passed away, passed on, past, pushing up daisies, released, relics,
   reliquiae, remains, reposing, resting easy, run out, sainted,
   skeleton, sleeping, smitten with death, stiff, still, stillborn,
   subtracted, taken away, taken off, tenement of clay, the dead,
   the deceased, the defunct, the departed, the loved one, vanished,
   wanting, with the Lord, with the saints, without life,
   without vital functions, wound up