[1] : The Collaborative International Dictionary of English v.0.48

decode \decode\ v. t.
   to convert from a coded form into the original form; -- of
   communications. inverse of encode.

   syn: decrypt, decipherwe1.
        pjc

[2] : WordNet (r) 2.0

decode
     v : convert code into ordinary language syn: decrypt, decipher
         ant: encode
see also:
decrypt decipher encode 

[3] : Moby Thesaurus II by Grady Ward, 1.0

54 moby thesaurus words for "decode":
   anagram, answer, bottom, break, clear up, crack, cryptanalyze,
   debug, decipher, decrypt, disentangle, divine, do, dope, dope out,
   elucidate, explain, fathom, figure out, find out, find the answer,
   find the solution, get, get right, guess, guess right, have it,
   hit it, interpret, make out, open the lock, plumb, psych,
   psych out, puzzle out, ravel, ravel out, render, resolve, riddle,
   solve, sort out, translate, undo, unfold, unlock, unravel,
   unriddle, unscramble, untangle, untwist, unweave, work, work out

Decode >> D Words
Decode, definition of term: Decode
decode_pag1.html