The Collaborative International Dictionary of English v.0.48:

Ravel \Rav"el\, v. i.
   1. To become untwisted or unwoven; to be disentangled; to be
      relieved of intricacy.
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   2. To fall into perplexity and confusion. [Obs.]
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            Till, by their own perplexities involved,
            They ravel more, still less resolved. --Milton.
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   3. To make investigation or search, as by picking out the
      threads of a woven pattern. [Obs.]
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            The humor of raveling into all these mystical or
            entangled matters.                    --Sir W.
                                                  Temple.
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The Collaborative International Dictionary of English v.0.48:

Ravel \Rav"el\ (r[a^]v"'l), v. t. [imp. & p. p. Raveled (-'ld)
   or Ravelled; p. pr. & vb. n. Raveling or Ravelling.]
   [OD. ravelen, D. rafelen, akin to LG. rebeln, rebbeln,
   reffeln.]
   1. To separate or undo the texture of; to unravel; to take
      apart; to untwist; to unweave or unknit; -- often followed
      by out; as, to ravel a twist; to ravel out a stocking.
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            Sleep, that knits up the raveled sleave of care.
                                                  --Shak.
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   2. To undo the intricacies of; to disentangle.
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   3. To pull apart, as the threads of a texture, and let them
      fall into a tangled mass; hence, to entangle; to make
      intricate; to involve.
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            What glory's due to him that could divide
            Such raveled interests? has the knot untied?
                                                  --Waller.
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            The faith of very many men seems a duty so weak and
            indifferent, is so often untwisted by violence, or
            raveled and entangled in weak discourses! --Jer.
                                                  Taylor.
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WordNet (r) 3.0 (2006):

Ravel
    n 1: French composer and exponent of Impressionism (1875-1937)
         [syn: Ravel, Maurice Ravel]
    2: a row of unravelled stitches; "she got a run in her stocking"
       [syn: run, ladder, ravel]
    v 1: disentangle; "can you unravel the mystery?" [syn: ravel,
         unravel, ravel out] [ant: knot, ravel, tangle]
    2: tangle or complicate; "a ravelled story" [syn: ravel,
       tangle, knot] [ant: ravel, ravel out, unknot,
       unpick, unravel, unscramble, untangle]

Moby Thesaurus II by Grady Ward, 1.0:

98 Moby Thesaurus words for "ravel":
   Chinese puzzle, Gordian knot, Rube Goldberg contraption, answer,
   ball up, bottom, can of worms, clarify, clear up, complex,
   complicate, confound, confuse, crack, debug, decipher, decode,
   disembroil, disentangle, disintricate, disinvolve, divine, do,
   dope, dope out, embrangle, entangle, explain, fathom, figure out,
   find out, find the answer, find the solution, foul up, get,
   get right, guess, guess right, have it, hit it, implicate,
   interpret, involve, jungle, knot, labyrinth, louse up, make out,
   maze, meander, mesh, mess, mess up, mix up, muck, muck up, muddle,
   open the lock, perplex, plumb, psych, psych out, puzzle out,
   ramify, ravel out, resolve, riddle, screw up, snafu, snake pit,
   snarl, snarl up, solve, sort out, tangle, tangled skein, unbraid,
   unclutter, uncoil, undo, unknot, unlock, unmix, unravel, unriddle,
   unscramble, unsnarl, untangle, unthread, untwine, untwist, unweave,
   unwind, webwork, wheels within wheels, wilderness, work,
   work out