WordNet (r) 3.0 (2006):

unscramble
    v 1: make intelligible; "Can you unscramble the message?" [ant:
         scramble]
    2: become or cause to become undone by separating the fibers or
       threads of; "unravel the thread" [syn: unravel, unknot,
       unscramble, untangle, unpick] [ant: knot, ravel,
       tangle]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "unscramble":
   answer, bottom, clarify, clear, clear up, crack, debug, decipher,
   decode, disburden, disembarrass, disembroil, disencumber,
   disengage, disentangle, disintricate, disinvolve, divine, do, dope,
   dope out, explain, extricate, fathom, figure out, find out,
   find the answer, find the solution, free, free up, get, get right,
   guess, guess right, have it, hit it, interpret, liberate, make out,
   open the lock, plumb, psych, psych out, puzzle out, ravel,
   ravel out, resolve, riddle, solve, sort out, unbraid, unclutter,
   uncoil, undo, unknot, unlock, unmix, unravel, unriddle, unsnarl,
   untangle, unthread, untwine, untwist, unweave, unwind, work,
   work out