The Collaborative International Dictionary of English v.0.48:

Sot \Sot\, n. [F., fr. LL. sottus; of unknown origin, cf. Ir.
   sotal pride, soithir proud, or Chald. & NHeb. shoten
   foolish.]
   1. A stupid person; a blockhead; a dull fellow; a dolt.
      [Obs.] --outh.
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            In Egypt oft has seen the sot bow down,
            And reverence some d?ified baboon.    --Oldham.
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   2. A person stupefied by excessive drinking; an habitual
      drunkard. "A brutal sot." --Granville.
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            Every sign
            That calls the staring sots to nasty wine.
                                                  --Roscommon.
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The Collaborative International Dictionary of English v.0.48:

Sot \Sot\, a.
   Sottish; foolish; stupid; dull. [Obs.] "Rich, but sot."
   --Marston.
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The Collaborative International Dictionary of English v.0.48:

Sot \Sot\, v. t.
   To stupefy; to infatuate; to besot. [R.]
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         I hate to see a brave, bold fellow sotted. --Dryden.
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The Collaborative International Dictionary of English v.0.48:

Sot \Sot\, v. i.
   To tipple to stupidity. [R.] --Goldsmith.
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WordNet (r) 3.0 (2006):

sot
    n 1: a chronic drinker [syn: drunkard, drunk, rummy,
         sot, inebriate, wino]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "sot":
   alcoholic, alcoholic addict, bacchanal, bacchanalian, bibber,
   big drunk, boozehound, boozer, bullheaded, carouser,
   chronic alcoholic, chronic drunk, closed-minded, deaf,
   devotee of Bacchus, dipsomaniac, drinker, drunk, drunkard, guzzler,
   hard drinker, hardheaded, headstrong, heavy drinker, imbiber,
   inebriate, intractable, lovepot, lush, mulish, oenophilist,
   pathological drinker, pot companion, problem drinker, reveler,
   serious drinker, shikker, soak, soaker, social drinker, swigger,
   swiller, thirsty soul, tippler, toper, tosspot, wassailer,
   winebibber