Source : Webster's Revised Unabridged Dictionary (1913)

Unravel \Un*rav"el\, v. t. [1st pref. un- (intensive) + ravel.]
   1. To disentangle; to disengage or separate the threads of;
      as, to unravel a stocking.

   2. Hence, to clear from complication or difficulty; to
      unfold; to solve; as, to unravel a plot.

   3. To separate the connected or united parts of; to throw
      into disorder; to confuse. ``Art shall be conjured for it,
      and nature all unraveled.'' --Dryden.

Unravel \Un*rav"el\, v. i.
   To become unraveled, in any sense.

Source : WordNet®

unravel
     v 1: become or cause to become undone by separating the fibers or
          threads of; "the sweater unravelled" [syn: {unknot}, {unscramble},
           {untangle}, {unpick}] [ant: {ravel}, {ravel}]
     2: disentangle; "can you unravel the mystery?"; "unravel the
        ball or yarn" [syn: {ravel}, {ravel out}]
     3: become undone; "the sweater unraveled" [syn: {run}]
     [also: {unravelling}, {unravelled}]