adjectiveold-fashioned or offensiveuk/ˌmen.təl.i dɪˈfek.tɪv/us/ˌmen.t̬əl.i dɪˈfek.tɪv/
有心理缺陷的,有智力缺陷的
a term to describe a person who finds it very difficult to learn and understand things, which was used by doctors in the past but is now often considered offensive