The Collaborative International Dictionary of English v.0.48:

Scabby \Scab"by\, a. [Compar. Scabbier; superl. Scabbiest.]
   1. Affected with scabs; full of scabs.
      [1913 Webster]

   2. Diseased with the scab, or mange; mangy. --Swift.
      [1913 Webster]

WordNet (r) 3.0 (2006):

scabby
    adj 1: covered with scabs

Moby Thesaurus II by Grady Ward, 1.0:

117 Moby Thesaurus words for "scabby":
   abject, abominable, arrant, asperous, atrocious, barfy, base,
   beggarly, blemished, checked, cheesy, cicatrized, contemptible,
   cracked, crappy, crazed, crummy, debased, defaced, defective,
   deformed, degraded, depraved, despicable, dirty, disfigured,
   disgusting, distorted, execrable, faulty, fecal, feculent, fetid,
   filthy, flagrant, flaky, flawed, flocculent, flyblown, foul,
   fulsome, furfuraceous, gloppy, grave, gross, gunky, heinous, icky,
   keloidal, kinked, lentiginous, lepidote, little, low, low-down,
   lumpen, maggoty, malodorous, mangy, marred, mean, measly, mephitic,
   miserable, monstrous, mucky, nasty, nauseating, nefarious,
   obnoxious, odious, ordurous, paltry, petty, pimpled, pimply, poky,
   poor, puky, putrid, rank, reptilian, repulsive, rotten, scabbed,
   scabious, scabrous, scaly, scarified, scarred, scrubby, scruffy,
   scummy, scurfy, scurvy, shabby, shitty, shoddy, slabby, slimy,
   sloppy, sloshy, sludgy, slushy, small, split, sposhy, squalid,
   squamous, twisted, unmentionable, vile, vomity, warped, wormy,
   wretched, yecchy