Down syndrome
WordNet
noun
(1) A congenital disorder caused by having an extra 21st chromosome; results in a flat face and short stature and mental retardation
WiktionaryText
Etymology
Named after John L.H. Langdon-Down (1828-1896), an English physician who described it in the late 1800s. The term was first used in 1961.
Noun
- Condition caused by a chromosomal excess, whereby the patients bear a certain resemblance to the Mongoloid race, such as a small head and tilted eyelids.