Mismatch (noun)

1. A pairing or combination of things that do not fit or go well together.
2. A difference or disparity between two things or people.

Origin:

From mis- ("wrong") + match ("a match, a pairing"), from middle english macche, from old english gemǣcc.

Examples:

1. The mismatched socks made him late for work.
2. The colors in the room were a mismatch and clashed with each other.
3. The company was in the middle of a mismatch between its employees and management.
4. The couple quickly realized that they were a mismatch and ended the relationship.
5. The company faced a mismatch between its expectations and the reality of the market.