adj. mentally deficient

adj. retarded in intellectual development

adj. slow to learn or understand; lacking intellectual acuity; "so dense he never understands anything I say to him"; "never met anyone quite so dim"; "although dull at classical learning, at mathematics he was uncommonly quick"- Thackeray; "dumb officials make some really dumb decisions"; "he was either normally stupid or being deliberately obtuse"; "worked with the slow students"

adj. relatively slow in mental or emotional or physical development; "providing a secure and sometimes happy life for the retarded"

adj. mentally or physically infirm with age; "his mother was doddering and frail"

adj. (used of timepieces) indicating a time earlier than the correct time; "the clock is slow"

adj. slow to learn or understand; lacking intellectual acuity; "so dense he never understands anything I say to him"; "never met anyone quite so dim"; "although dull at classical learning, at mathematics he was uncommonly quick"- Thackeray; "dumb officials make some really dumb decisions"; "he was either normally stupid or being deliberately obtuse"; "worked with the slow students"

adj. so lacking in interest as to cause mental weariness; "a boring evening with uninteresting people"; "the deadening effect of some routine tasks"; "a dull play"; "his competent but dull performance"; "a ho-hum speaker who couldn't capture their attention"; "what an irksome task the writing of long letters is"- Edmund Burke; "tedious days on the train"; "the tiresome chirping of a cricket"- Mark Twain; "other people's dreams are dreadfully wearisome"

adj. not using intelligence

adj. having a mental age of three to seven years

adj. having a mental age of between eight and twelve years

adj. afflicted with cretinism

adj. lacking mental capacity and subtlety

adj. characterized by or characteristic of exceptionally early development or maturity (especially in mental aptitude); "a precocious child"; "a precocious achievement"