slang A foolish, stupid, or idiotic person—i.e., someone with putty for brains. Sometimes hyphenated or spelled as a single word. It's no surprise to me that the country's economy is tanking with that putty head in charge. How can you be such a putty head about this? Only a putty-head like you would think that.
n. a stupid person. (As if the person’s head were soft as putty. Also a term of address.) Look, you silly puttyhead, shut up!