Definition
A 'dunderhead' is a stupid or foolish person; it's a more colorful and less harsh way to call someone an idiot. It suggests a lack of intelligence or common sense, but with a touch of humor. Think of it as a lighthearted insult, like calling someone a goofball. It's stronger than 'duffer' but not as mean as 'dunce.' Imagine someone making a silly mistake and you playfully calling them a 'dunderhead.'