meathead

Etymology

From meat + head. The term meathead is often said to come from the classic 1970s television situation comedy All In The Family, wherein main character Archie Bunker (Carroll O'Connor) used the nickname to address his son-in-law, Michael Stivic (Rob Reiner), starting with the premiere episode ("Meet the Bunkers") that first aired January 12, 1971. The term is also used three times in the "Star Witness" episode of the television situation comedy Green Acres, an episode that first aired January 26, 1971, exactly two weeks after the premiere of All in the Family. However, the word appeared in writing as early as 1863.

noun

1. (slang) An ungainly, dull or stupid person; someone who is lazy, disrespectful and/or whose beliefs and philosophies clash with another.
2. (slang) A large, muscular, stupid man, especially an athlete.
   Gary was a hulking meathead who, when he wasn't playing football, was either hunting, fishing or getting drunk and rowdy in some topless bar.
3. (military, slang, Canada) A member of the Canadian Forces Military Police.