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.
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   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.
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   3. Rough; dark; tempestuous.
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            Now softened into joy the surly storm. --Thomson.
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