The action of scribble, v.1 (in various senses).

A scribbled or scrawled message, drawing, etc.; (also) a worthless or trivial piece of writing. Also as a mass noun: worthless or trivial writing.

The action of scrawl, v.2; scribbling, careless untidy writing.

A careless, illegible style of handwriting.

plural. Scrawled or illegible characters. Obsolete.

plural humorously. Characters or writing difficult to make out. Cf. hieroglyph, n. 2b.

Illegible writing.

A rough or irregular mark made by a pencil, paint-brush, etc.; hence, a slight sketch, a hasty scrawl.

unintelligible writing, scrawl.

A scratch-like mark, esp. a piece of untidy or illegible handwriting; a hen scratch (hen scratch, n. 3). Obsolete. rare.

A piece of cryptographic writing; anything written in code or cipher.

Irregular or untidy handwriting, esp. that which is produced quickly or carelessly; an example of this. Also: a word, phrase, etc., written in…

Scribble.

Chiefly U.S. colloquial. A scratch-like mark or series of marks; spec. cramped, untidy, or illegible handwriting. Cf. hen scratch, n. 3.

In plural or as a mass noun: unintelligible, illegible, or roughly-drawn marks, lines, symbols, or letters, typically made by hand; illegible…

humorously. A piece of writing difficult to decipher.