The Collaborative International Dictionary of English v.0.48:

Somewhat \Some"what`\, adv.
   In some degree or measure; a little.
   [1913 Webster]

         His giantship is gone, somewhat crestfallen. --Milton.
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         Somewhat back from the village street.   --Longfellow.
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The Collaborative International Dictionary of English v.0.48:

Somewhat \Some"what`\, n.
   1. More or less; a certain quantity or degree; a part, more
      or less; something.
      [1913 Webster]

            These salts have somewhat of a nitrous taste.
                                                  --Grew.
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            Somewhat of his good sense will suffer, in this
            transfusion, and much of the beauty of his thoughts
            will be lost.                         --Dryden.
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   2. A person or thing of importance; a somebody.
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            Here come those that worship me.
            They think that I am somewhat.        --Tennyson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

somewhat
    adv 1: to a small degree or extent; "his arguments were somewhat
           self-contradictory"; "the children argued because one
           slice of cake was slightly larger than the other" [syn:
           slightly, somewhat, more or less]
    2: to a moderately sufficient extent or degree; "pretty big";
       "pretty bad"; "jolly decent of him"; "the shoes are priced
       reasonably"; "he is fairly clever with computers" [syn:
       reasonably, moderately, pretty, jolly, somewhat,
       fairly, middling, passably] [ant: immoderately,
       unreasonably]