The Collaborative International Dictionary of English v.0.48:

Surly \Sur"ly\ (s[^u]r"l[y^]), a. [Compar. Surlier
   (s[^u]r"l[i^]*[~e]r); superl. Surliest.] [Probably from
   sir, and originally meaning, sirlike, i.e., proud. See Sir,
   and Like, a.]
   1. Arrogant; haughty. [Obs.] --Cotgrave.
      [1913 Webster]

   2. Gloomily morose; ill-natured, abrupt, and rude; severe;
      sour; crabbed; rough; sullen; gloomy; as, a surly groom; a
      surly dog; surly language; a surly look. "That surly
      spirit, melancholy." --Shak.
      [1913 Webster]

   3. Rough; dark; tempestuous.
      [1913 Webster]

            Now softened into joy the surly storm. --Thomson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

surly
    adj 1: inclined to anger or bad feelings with overtones of
           menace; "a surly waiter"; "an ugly frame of mind" [syn:
           surly, ugly]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "surly":
   abrupt, aggressive, argumentative, bad-tempered, bearish, beastly,
   beetle-browed, bilious, black, black-browed, bluff, blunt, boorish,
   brash, brusque, cantankerous, cavalier, choleric, churlish,
   crabbed, crabby, cross, crotchety, crusty, curt, dark, dejected,
   discourteous, dour, dumpish, dyspeptic, fractious, frowning,
   glowering, glum, grim, grouchy, gruff, grum, grumpy, harsh,
   ill-humored, ill-mannered, ill-natured, ill-tempered, irritable,
   lowering, melancholy, moodish, moody, mopey, moping, mopish,
   morose, mumpish, obnoxious, obstreperous, peevish, quarrelsome,
   rough, rude, saturnine, scowling, severe, sharp, short,
   short-tempered, snappish, snippy, splenetic, sulky, sullen,
   temperamental, testy, touchy, truculent, ugly, uncivil, ungracious,
   unpleasant, waspish