The Collaborative International Dictionary of English v.0.48:

Grabble \Grab"ble\, v. i. [imp. & p. p. Grabbled; p. pr. & vb.
   n. Grabbling.] [Freq. of grab; cf. D. grabbelen.]
   1. To grope; to feel with the hands.
      [1913 Webster]

            He puts his hands into his pockets, and keeps a
            grabbling and fumbling.               --Selden.
      [1913 Webster]

   2. To lie prostrate on the belly; to sprawl on the ground; to
      grovel. --Ainsworth.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "grabble":
   beat about, bring in, crop, crop herbs, cut, dig, feel,
   feel around, feel for, fumble, gather, gather in, glean, grope,
   grope for, harvest, hay, mow, nut, pick, pluck, poke around,
   pry around, reap, reap and carry, scrabble