Wiktionary
muttonheaded
n. (context British slang English) Being a muttonhead; stupid or foolish.
Usage examples of "muttonheaded".
Only death will part me from my husband, not muttonheaded, well-meaning, misguided Englishmen or Scotsmen or stubborn Spanish sea captains!
I can well imagine that it's your dearest wish to see that unfortunate muttonheaded girl become the wife of a man who lets off stink bombs in night clubs and pinches the spoons and has had three divorces already and who, if the authorities play their cards right, will end up cracking rocks in Sing-Sing.