Definition & Meaning of "dunderhead"in English

What is the origin of the term "dunderhead" and how is it used?

"Dunderhead" is an English slang term that dates back to the 16th century, combining "dunder," an old word for a block of wood or stupidity, with "head," implying someone with a thick or slow mind. It came to describe a person who is stupid, foolish, or dull-witted. The term appears in literature, everyday speech, and moral or humorous critique. It is mildly derogatory and often playful, more teasing than harsh, and not highly offensive.