Mongolian idiocy

The obsolete medical terms Mongolian idiocy and Mongolism referred to a specific type of mental deficiency, associated with the genetic disorder now known as Down syndrome. The obsolete term for a person with this syndrome was called a Mongolian idiot.

In the 21st century, those terms are no longer used as medical terminology, deemed an unacceptable, offensive and misleading description of those with Down syndrome. The terminology change was brought about both by scientific and medical experts, as well as people of Asian ancestry, including those from Mongolia.

The stand-alone term "idiot" itself has a similar history of meaning and connotation change.