cretin
From Longman Dictionary of Contemporary Englishcretincret‧in /ˈkretɪn $ ˈkriːtn/ noun [countable] STUPID/NOT INTELLIGENT informal not polite an offensive word for someone who is extremely stupidOrigin cretin (1700-1800) French crétin, from French dialect cretin “Christian, human being, type of mentally affected person who lives in the Alps”, from Latin christianus “Christian”