Meathead

Noun

 * 1)  An ungainly, dull or stupid person; someone who is lazy, disrespectful and/or whose beliefs and philosophies clash with another.
 * 2)  A large, muscular, stupid male, especially an athlete. A jock. A brute.
 * 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.

Thesaurus
addlebrain, addlehead, addlepate, beefhead, blockhead, blubberhead, blunderhead, bonehead, bufflehead, cabbagehead, chowderhead, chucklehead, clodhead, clodpate, clodpoll, dolthead, dullhead, dumbhead, dunderhead, dunderpate, fathead, gaum, gawk, jolterhead, jughead, klutz, knucklehead, lobster, looby, lout, lubber, lump, lunkhead, muddlehead, mushhead, muttonhead, noodlehead, numskull, oaf, palooka, peabrain, pinbrain, pinhead, puddinghead, pumpkin head, puzzlehead, stupidhead, thickhead, thickskull, tottyhead

Etymology
The term meathead is often credited as coming 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). However, the word appeared in writing as early as 1863.