scrawl

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To write hastily or sloppily.
• intransitive verb To write something in a hasty or sloppy manner.
• noun Sloppy, often illegible handwriting.
• noun Something, such as a note, written hastily or sloppily.

from The Century Dictionary.

• To draw or mark awkwardly and irregularly with a pen, pencil, or other marking implement; write awkwardly, hastily, or carelessly; scribble: as, to scrawl a letter; also, to make irregular lines or bad writing on: as, to scrawl a piece of paper.
• To mark with irregular wandering or zigzag lines: as, eggs scrawled with black (natural marking).
• To write unskilfully and inelegantly.
• noun A piece of unskilful or inelegant writing; also, a piece of hasty, bad writing.
• noun In law, same as scroll-seal.
• noun The young of the dog-crab.
• noun A trawl.
• To creep; crawl; by extension, to swarm with crawling things.
• noun A ragged, broken branch of a tree; brushwood.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb obsolete See crawl.
• noun Unskillful or inelegant writing; that which is unskillfully or inelegantly written.
• intransitive verb To write unskillfully and inelegantly.
• transitive verb To draw or mark awkwardly and irregularly; to write hastily and carelessly; to scratch; to scribble.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An Irregular, possibly illegible handwriting.
• noun A hastily, or carelessly written note etc.
• verb transitive To write something hastily or illegibly.
• verb intransitive To write in an irregular or illegible manner.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun poor handwriting
• verb write carelessly