muttonheaded

1. (British, slang) Being a muttonhead; stupid or foolish.
   • 1960, P[elham] G[renville] Wodehouse, chapter XVII, in Jeeves in the Offing, London: Herbert Jenkins, OCLC 1227855 ↗:

     “And I suppose you're delighted?” “Of course I am.” “Yes, of course you are! 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. That is unless the loony-bin gets its bid in first. Just a Prince Charming, you might say.”