Down syndrome

or Down's syndrome

noun

, Pathology.

1. a genetic disorder, associated with the presence of an extra chromosome 21, characterized by mild to severe mental impairment, weak muscle tone, shorter stature, and a flattened facial profile.

Sensitive Note

Down syndrome (or Down's syndrome ) has replaced earlier terms, such as mongolism to refer to the disease and Mongoloid or Mongol to refer to the affected person, all of which are now considered offensive.

Word History and Origins

Origin of Down syndrome¹

First recorded in 1960–65; after John L. H. Down (1828–96), British physician