bonehead



Definition: An unintelligent person; someone who does stupid things

Example: 1) Jason put his hand right in the fire. What a bonehead

That bonehead doesn't know his right from his left

Etymology: The outside part of your head (skull) is made of bone, which protects your brain. If your whole head were made of bone, and you didn't have a brain, you wouldn't be very intelligent. A 'bonehead' is someone with all bone, no brain