The Collaborative International Dictionary of English v.0.48:

bushed \bushed\ (b[.u]sht), pred. adj.
   very tired from exertion.

   Syn: all in(predicate), beat(predicate), dead(predicate),
        dead tired(predicate), knocked out(predicate).
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Bush \Bush\, v. t. [imp. & p. p. Bushed (b[.u]sht); p. pr. &
   vb. n. Bushing.]
   1. To set bushes for; to support with bushes; as, to bush
      peas.
      [1913 Webster]

   2. To use a bush harrow on (land), for covering seeds sown;
      to harrow with a bush; as, to bush a piece of land; to
      bush seeds into the ground.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bushed
    adj 1: very tired; "was all in at the end of the day"; "so beat
           I could flop down and go to sleep anywhere"; "bushed
           after all that exercise"; "I'm dead after that long trip"
           [syn: all in(p), beat(p), bushed(p), dead(p)]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "bushed":
   all in, beat, beat up, beaten, bone-weary, dead, dead-and-alive,
   dead-tired, deadbeat, dog-tired, dog-weary, done, done in, done up,
   drained, exhausted, fagged out, gone, knocked out, played out,
   pooped, pooped out, prostrate, ready to drop, spent, tired out,
   tired to death, tuckered out, used up, washed-up, weary unto death,
   whacked, wiped out, worn-out