What does butthead mean?

butthead meaning in Etymology Dictionary

additionally butt-head, late 1980s, student slang, "objectionable person," from butt (n.1) + mind (n.); perhaps affected by butterhead, 1960s black slang for starters who's a disgrace towards the community. Early in the day, butthead intended simply "the butt end, bottom" of any such thing (1630s).