Dictionary:

messy

  (mĕs'ē)

1. Disorderly and dirty: a messy bedroom.
2. Exhibiting or demonstrating carelessness: messy reasoning.
3. Unpleasantly difficult to settle or resolve: a messy court case.

adjective

1. Marked by an absence of cleanliness and order: disheveled, mussy, slipshod, sloppy, slovenly, unkempt, untidy. See order/disorder.
2. Indifferent to correctness, accuracy, or neatness: careless, slapdash, slipshod, sloppy, slovenly, untidy. See careful/careless.
3. Lacking regular or logical order: disorderly, unsystematic. See order/disorder.

Definition: cluttered, dirty
Antonyms: clean, ordered, orderly, organized, tidy, uncluttered

The adjective has one meaning:

Meaning #1: dirty and disorderly
  Synonym: mussy