- The definition of messy is something that is disorderly or dirty.
An example of something messy is a teenager's bedroom.
A very messy closet.
- a. Disorderly and dirty: a messy bedroom.b. Given to making messes; not neat or organized: a messy roommate.
- Exhibiting or demonstrating carelessness: messy reasoning.
- Unpleasantly difficult to settle or resolve: a messy court case.
(comparative messier, superlative messiest)