A foolish or stupid person.
The word knucklehead comes from the word "knuckle" referring to the joints of the fingers and "head" referring to a person. the word is an informal term used to describe a person who is foolish or stupid.
- He was a knucklehead, always getting into trouble.
- She couldn't believe he fell for that scam, what a knucklehead.
- The knucklehead left his keys in the car and it got stolen.
- He was a knucklehead, always making the same mistakes.
- The knucklehead got lost on his way home, despite having a GPS.