Muttonhead is an old-fashioned term used to describe someone who is foolish or slow-witted. The crossword solutions for this term are OAF (3 letters), LUNK (4 letters), ASS (3 letters), SAP (3 letters), and DOLT (4 letters). OAF stands for 'Oddly Apathetic Fool', LUNK is a slang term for a clumsy or stupid person, ASS is a derogatory term for a foolish or stupid person, SAP is a slang term for a gullible or naive person, and DOLT is a derogatory term for a stupid or foolish person. All of these terms are used to describe someone who is foolish or slow-witted, which is the definition of muttonhead.