muss

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

• transitive verb To make messy or untidy; rumple.
• noun A state of disorder; a mess.

from The Century Dictionary.

• noun A scramble, as for small objects thrown down to be taken by those who can seize them.
• noun That which is to be scrambled for.
• noun A state of confusion; disorder: as, the things are all in a muss.
• noun An indiscriminate fight; a squabble; a row.
• noun A mouse: used as a term of endearment.
• To put into a state of disorder; rumple; tumble: as, to muss one's hair.
• To smear; mess.

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

• noun A scramble, as when small objects are thrown down, to be taken by those who can seize them; a confused struggle.
• noun Colloq. U.S. A state of confusion or disorder; -- prob. variant of mess, but influenced by muss, a scramble.
• noun obsolete A term of endearment.
• transitive verb Colloq. U.S. To disarrange, as clothing; to rumple; -- often used with up.

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

• verb transitive to rumple, tousle or make (something) untidy
• noun a disorderly mess
• noun obsolete A term of endearment.

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

• verb make messy or untidy
• noun a state of confusion and disorderliness