a person who is notably stupid or lacking in good judgment.

Psychology . a person of borderline intelligence in a former classification of mental retardation, having an intelligence quotient of 50 to 69.

noun

brain

noun

addlepate , blockhead * , boob * , dimwit , dingbat , dolt , dope * , dork , dumbbell * , dummy * , dunce , fool , halfwit , idiot , ignoramus , imbecile , lamebrain * , loony * , loser * , mental defective , nerd * , simpletonnotes:an idiot is a stupid person with a mental age below three years , while a moron is a stupid person with a mental age of between seven to twelve years , ass , jackass , mooncalf , nincompoop , ninny , nitwit , simple , simpleton , softhead , tomfool , blockhead , boob , dull , numskull , stupid , supposition