The Collaborative International Dictionary of English v.0.48:

Wet \Wet\, v. t. [imp. & p. p. Wet (rarely Wetted); p. pr. &
   vb. n. Wetting.] [AS. w[=ae]tan.]
   To fill or moisten with water or other liquid; to sprinkle;
   to cause to have water or other fluid adherent to the
   surface; to dip or soak in a liquid; as, to wet a sponge; to
   wet the hands; to wet cloth. "[The scene] did draw tears from
   me and wetted my paper." --Burke.
   [1913 Webster]

         Ye mists and exhalations, that now rise . . .
         Whether to deck with clouds the uncolored sky,
         Or wet the thirsty earth with falling showers.
                                                  --Milton.
   [1913 Webster]

   To wet one's whistle, to moisten one's throat; to drink a
      dram of liquor. [Colloq.]
      [1913 Webster]

            Let us drink the other cup to wet our whistles.
                                                  --Walton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

wetting
    n 1: the act of making something wet
    2: a euphemism for urination; "he had to take a leak" [syn:
       leak, wetting, making water, passing water]