The Collaborative International Dictionary of English v.0.48:

Unkempt \Un*kempt"\ (?; 215), a. [Pref. un- not + kempt, p. p.
   of kemb.]
   1. Not combed; disheveled; as, an urchin with unkempt hair.
      [1913 Webster]

   2. Fig.; Not smoothed; unpolished; rough.
      [1913 Webster]

            My rhymes be rugged and unkempt.      --Spenser.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unkempt
    adj 1: not neatly combed; "wild unkempt hair"
    2: not properly maintained or cared for; "an unkempt garden";
       "native vistas and unkempt rambling paths"; "an ukempt
       appearance"

Moby Thesaurus II by Grady Ward, 1.0:

112 Moby Thesaurus words for "unkempt":
   Gothic, Neanderthal, animal, barbarian, barbaric, barbarous,
   beat-up, bedraggled, bestial, blowzy, broken, brutal, brutish,
   bumpy, careless, chintzy, choppy, coarse, coarse-grained,
   corrugated, cross-grained, dilapidated, disarranged, disheveled,
   disordered, drabbletailed, draggled, draggletailed, frowzy,
   frumpish, frumpy, grainy, granulated, grubby, homespun,
   horripilant, ill-bred, impolite, in rags, inequal, informal,
   irregular, jolty, linsey-woolsey, loose, lumpen, messy, mussy,
   negligent, noncivilized, outlandish, pimply, pitted, pocky, poky,
   potholed, primitive, ragged, raggedy, rank, ripply, rough,
   rough-and-ready, rough-cast, rough-grained, rough-hewn, ruffled,
   ruinous, rumpled, rutted, rutty, savage, scraggly, scruffy, seedy,
   shabby, shagged, shaggy, shoddy, slack, slatternly, slipshod,
   sloppy, slovenly, sluttish, sordid, squalid, tacky, tattered,
   textured, tousled, troglodytic, uncivil, uncivilized, uncombed,
   uncouth, uncultivated, uncultured, uneven, unfastidious, unlevel,
   unlicked, unneat, unpolished, unrefined, unsightly, unsmooth,
   untamed, untidy, ununiform, wild, wimpled