The Collaborative International Dictionary of English v.0.48:

burned-out \burned-out\ burnt-out \burnt-out\adj. prenom.
   1. drained of energy or effectiveness; driven to apathy by
      overwork or prolonged stress; -- of people.

   Syn: burned out(predicate), burnt out(predicate), fagged,
        exhausted, fatigued, played-out(prenominal), played
        out(predicate), spent, washed-out(prenominal), washed
        out(predicate), worn-out(prenominal), worn
        out(predicate).
        [WordNet 1.5]

   2. damaged or destroyed by or as if by fire; as, barricaded
      the street with burned-out cars.

   Syn: burned out(predicate), burnt out(predicate).
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

burned-out
    adj 1: exhausted as a result of longtime stress; "she was
           burned-out before she was 30" [syn: burned-out, burnt-
           out]
    2: inoperative as a result of heat or friction; "a burned-out
       picture tube" [syn: burned-out, burnt-out]
    3: destroyed or badly damaged by fire; "a row of burned houses";
       "a charred bit of burnt wood"; "a burned-over site in the
       forest"; "barricaded the street with burnt-out cars" [syn:
       burned, burnt, burned-over, burned-out, burnt-out]