Dimwit (noun)

A stupid or foolish person.

Origin:

The word dimwit is a slang term of uncertain origin, it first appears in early 20th century.

Examples:

1. He was considered a dimwit by his colleagues because of his lack of intelligence.
2. She couldn't believe he fell for that scam, what a dimwit!
3. He was criticized for being a dimwit, because he couldn't understand simple instructions.
4. She was called a dimwit by her friends, because she always made poor decisions.
5. He was known as a dimwit in the office, never showing any initiative or intelligence.