WordWeb Online

1. A stupid person; used to express a low opinion of someone's intelligence
   - dunce, dunderhead [informal], numskull [informal], blockhead [informal], bonehead [informal], lunkhead [N. Amer], hammerhead [informal], knucklehead [informal], loggerhead [archaic], muttonhead [informal], dumbass [N. Amer], chowderhead [N. Amer, informal], chucklehead [informal], lamebrain [informal], numbskull [informal], bubblehead [informal], dumbhead [N. Amer, informal], clunk [N. Amer, informal], twonk [Brit, informal], dumbo [informal], lunk [N. Amer, informal]

Type of: dolt [informal], dullard, meatball [N. Amer, informal], pillock [Brit, informal], pudden-head [US, informal], pudding head [informal], stupe [N. Amer, informal], stupid, stupid person