n. 笨蛋

[ noun ]
a stupid person; these words are used to express a low opinion of someone's intelligence
<noun.person>

Dunderhead \Dun"der*head`\, n. [Prov. Eng. also dunderpoll, from
dunder, same as thunder.]
A dunce; a numskull; a blockhead. --Beau. & Fl.