idiot/idiocy

because the term "idiot" is unscientific, highly demeaning, and always unacceptable, use instead someone with profound mental retardation/mental impairment/a mental disability; mental impairment/disability. Also avoid abnormal, backward, feeble-minded, freak, imbecile, moron. For the casual insult, consider using blockhead, stupid, fool. See also disabilities, handicapped, normal, retard.