The Collaborative International Dictionary of English v.0.48:

Dabble \Dab"ble\, v. i.
   1. To play in water, as with the hands; to paddle or splash
      in mud or water.
      [1913 Webster]

            Where the duck dabbles 'mid the rustling sedge.
                                                  --Wordsworth.
      [1913 Webster]

   2. To work in slight or superficial manner; to do in a small
      way; to tamper; to meddle. "Dabbling here and there with
      the text." --Atterbury.
      [1913 Webster]

            During the first year at Dumfries, Burns for the
            first time began to dabble in politics. --J. C.
                                                  Shairp.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dabble \Dab"ble\ (d[a^]b"b'l), v. t. [imp. & p. p. Dabbled
   (d[a^]b"b'ld); p. pr. & vb. n. Dabbling (d[a^]b"bl[i^]ng).]
   [Freq. of dab: cf. OD. dabbelen.]
   To wet by little dips or strokes; to spatter; to sprinkle; to
   moisten; to wet. "Bright hair dabbled in blood." --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

dabble
    v 1: dip a foot or hand briefly into a liquid
    2: play in or as if in water, as of small children [syn:
       dabble, paddle, splash around]
    3: work with in an amateurish manner; "She dabbles in
       astronomy"; "He plays around with investments but he never
       makes any money" [syn: dabble, smatter, play around]
    4: bob forward and under so as to feed off the bottom of a body
       of water; "dabbling ducks"

Moby Thesaurus II by Grady Ward, 1.0:

96 Moby Thesaurus words for "dabble":
   asperge, be innocent of, bedabble, bedew, beguile the time,
   bespatter, besprinkle, burn daylight, consume time, coquet,
   coquet with, dally, damp, dampen, dash, dew, diddle, dip, doodle,
   douche, fiddle, fiddle with, fiddle-faddle, fidget with,
   finger with, flirt, fool, fool around, fool with, footle, fribble,
   fritter away time, frivol, give up, have no idea, horse around,
   hose, hose down, humect, humectate, humidify, idle, irrigate,
   jerk off, kid around, kill time, know a little, know not,
   know not what, know nothing of, loiter, lose time, mess around,
   moisten, monkey, monkey around, not know, not rightly know, paddle,
   pass, pass the time, piddle, play, play around, play with, potter,
   putter, scratch the surface, slobber, slop, slosh, smatter, sparge,
   spatter, splash, splatter, splotch, sponge, spot, spray, sprinkle,
   swash, syringe, tinker, toy, toy with, trifle, trifle with,
   twiddle, waste time, water, wet, wet down, wonder, wonder whether,
   wot not of