The Collaborative International Dictionary of English v.0.48:

Scribble \Scrib"ble\, v. i.
   To write without care, elegance, or value; to scrawl.
   [1913 Webster]

         If Maevius scribble in Apollo's spite.   --Pope.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Scribble \Scrib"ble\, v. t. [Cf. Scrabble.] (Woolen Manuf.)
   To card coarsely; to run through the scribbling machine.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Scribble \Scrib"ble\, v. t. [imp. & p. p. Scribbled (-b'ld);
   p. pr. & vb. n. Scribbling (-bl[i^]ng).] [From Scribe.]
   1. To write hastily or carelessly, without regard to
      correctness or elegance; as, to scribble a letter.
      [1913 Webster]

   2. To fill or cover with careless or worthless writing.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Scribble \Scrib"ble\, n.
   Hasty or careless writing; a writing of little value; a
   scrawl; as, a hasty scribble. --Boyle.
   [1913 Webster]

         Neither did I but vacant seasons spend
         In this my scribble.                     --Bunyan.
   [1913 Webster]

WordNet (r) 3.0 (2006):

scribble
    n 1: poor handwriting [syn: scribble, scratch, scrawl,
         cacography]
    2: an aimless drawing [syn: scribble, scrabble, doodle]
    v 1: write down quickly without much attention to detail [syn:
         scribble, scrabble]
    2: write carelessly [syn: scribble, scrawl]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "scribble":
   anamorphosis, bad likeness, barbouillage, botch, burlesque,
   caricature, daub, distortion, doodle, hen scratches, hen tracks,
   illegibility, indecipherability, jot down, misdraw, mispaint,
   parody, pattes de mouche, pothookery, pothooks,
   pothooks and hangers, scrabble, scratch, scrawl, scribbling,
   scribe, squiggle, travesty, undecipherability, unreadability,
   write



The Jargon File (version 4.4.7, 29 Dec 2003):

scribble
 n.

    To modify a data structure in a random and unintentionally destructive way.
    ?Bletch! Somebody's disk-compactor program went berserk and scribbled on
    the i-node table.? ?It was working fine until one of the allocation
    routines scribbled on low core.? Synonymous with trash; compare mung,
    which conveys a bit more intention, and mangle, which is more violent and
    final.


The Free On-line Dictionary of Computing (30 December 2018):

scribble

   To modify a data structure in a random and unintentionally
   destructive way.  "Bletch! Somebody's disk-compactor program
   went berserk and scribbled on the i-node table."  "It was
   working fine until one of the allocation routines scribbled on
   low core."  Synonymous with trash; compare mung, which
   conveys a bit more intention, and mangle, which is more
   violent and final.

   [Jargon File]