The Collaborative International Dictionary of English v.0.48:

Unclear \Unclear\
   See clear.

WordNet (r) 3.0 (2006):

unclear
    adj 1: poorly stated or described; "he confuses the reader with
           ill-defined terms and concepts" [syn: ill-defined,
           unclear] [ant: clear, well-defined]
    2: not clear to the mind; "the law itself was unclear on that
       point"; "the reason for their actions is unclear to this day"
       [ant: clear]
    3: not easily deciphered; "indecipherable handwriting" [syn:
       indecipherable, unclear, undecipherable, unreadable]

Moby Thesaurus II by Grady Ward, 1.0:

122 Moby Thesaurus words for "unclear":
   aleatoric, aleatory, ambiguous, amorphic, amorphous,
   amphibological, anarchic, baggy, barely audible, blear, bleared,
   bleary, blind, blobby, blurred, blurry, broad, chance, chancy,
   chaotic, characterless, clear as mud, cloudy, confused, dark,
   decrescendo, dim, disordered, disorderly, distant, dubious,
   equivocal, faint, faint-voiced, featureless, feeble, filmy, foggy,
   formless, fuzzy, general, gentle, half-heard, half-seen,
   half-visible, hazy, hit-or-miss, ill-defined, illegible, imprecise,
   inaccurate, inchoate, incoherent, inconspicuous, indecipherable,
   indecisive, indefinable, indefinite, indeterminable, indeterminate,
   indistinct, indistinguishable, inexact, inform, kaleidoscopic, lax,
   loose, low, low-profile, lumpen, merely glimpsed, misty, muddy,
   murky, murmured, nebulous, nondescript, nonspecific, obscure,
   opaque, open, orderless, out of focus, pale, pianissimo, piano,
   problematic, random, scarcely heard, semivisible, shadowed forth,
   shadowy, shapeless, soft, soft-sounding, soft-voiced, stochastic,
   subaudible, subdued, suspect, sweeping, tenebrous, transcendent,
   uncertain, undecipherable, undefined, undestined, undetermined,
   unintelligible, unordered, unorganized, unplain, unreadable,
   unrecognizable, unsettled, unspecified, unsure, vague, veiled,
   weak, weak-voiced, whispered