fathead
ass, berk (Brit. slang) booby, charlie (Brit. informal) coot, dickhead (slang) dickwit (slang) dimwit (informal) dipstick (Brit. slang) divvy (Brit. slang) dope (informal) dork (slang) dunderhead, dweeb (U.S. slang) fool, fuckwit (taboo slang) geek (slang) gobshite (Irish taboo slang) gonzo (slang) goose, idiot, imbecile, jackass, jerk (slang, chiefly U.S. & Canad.) lamebrain (informal) nerd or nurd (slang) nincompoop, nitwit (informal) numbskull or numskull, numpty (Scot. informal) pillock (Brit. slang) plank (Brit. slang) plonker (slang) prat (slang) prick (derogatory slang) schmuck (U.S. slang) twerp or twirp (informal) twit (informal, chiefly Brit.) wally (slang)