The Collaborative International Dictionary of English v.0.48:

Scrabble \Scrab"ble\ (skr[a^]b"b'l), v. i. [imp. & p. p.
   Scrabbled; p. pr. & vb. n. Scrabbling.] [Freq. of scrape.
   Cf. Scramble, Scrawl, v. t.]
   1. To scrape, paw, or scratch with the hands; to proceed by
      clawing with the hands and feet; to scramble; as, to
      scrabble up a cliff or a tree.
      [1913 Webster]

            Now after a while Little-faith came to himself, and
            getting up made shift to scrabble on his way.
                                                  --Bunyan.
      [1913 Webster]

   2. To make irregular, crooked, or unmeaning marks; to
      scribble; to scrawl.
      [1913 Webster]

            David . . . scrabbled on the doors of the gate. --1.
                                                  Sam. xxi. 13.
      [1913 Webster]