- an utterly foolish or senseless person: If you think you can wear that outfit to a job interview and get hired, you're an idiot!
- (no longer in technical use; considered offensive) a person of the lowest order in a former and discarded classification of intellectual disability, having a mental age of less than three years old and an intelligence quotient under 25.
- a person with severe mental retardation
- a foolish or senseless person
