Bozo (noun)

1. A man who is considered foolish, incompetent, or clownish.
2. A man who lacks good judgment or common sense.

Origin:

The origin of the word bozo is uncertain, but it is likely to have originated in american slang in the early 20th century.

Examples:

1. He was such a bozo, he couldn't even change a tire.
2. Don't be such a bozo, think before you act.
3. He was always acting like a bozo, and never took anything seriously.
4. The boss was a real bozo, always making bad decisions.
5. The clown's name was Bozo, and he was a real bozo.