← BackshareGuessdimwit/ˈdɪmˌwɪt/nounA person who is not very smart or who does silly things.He locked his keys in the car again — what a dimwit.Don't be a dimwit; wear a helmet when you ride your bike.The movie's villain was a dimwit who kept making stupid mistakes.SynonymsduncefoolidiotAntonymsgenius