The Collaborative International Dictionary of English v.0.48:

Dewy \Dew"y\, a.
   1. Pertaining to dew; resembling, consisting of, or moist
      with, dew.
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            A dewy mist
            Went and watered all the ground.      --Milton.
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            When dewy eve her curtain draws.      --Keble.
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   2. Falling gently and beneficently, like the dew.
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            Dewy sleep ambrosial.                 --Cowper.
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   3. (Bot.) Resembling a dew-covered surface; appearing as if
      covered with dew.
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WordNet (r) 3.0 (2006):

dewy
    adj 1: wet with dew [syn: bedewed, dewy]