Airhead

An airhead is a derogatory slang term for a person considered to be unintelligent, frivolous, or lacking in common sense. The term typically implies a lack of intellectual depth and a preoccupation with superficial or trivial matters. It is often used to describe someone perceived as ditzy, scatterbrained, or naive. The term is generally considered offensive and should be used with caution. While historically the term has been more commonly applied to women, it can be used to describe people of any gender. The etymology likely stems from the idea that the person's head is filled with "air" instead of brains or substance.