Down syndrome

noun

variants or Down's syndrome

: a congenital condition characterized especially by developmental delays, usually mild to moderate impairment in cognitive functioning, short stature, upward slanting eyes, a flattened nasal bridge, broad hands with short fingers, decreased muscle tone, and by trisomy of the human chromosome numbered 21

called also trisomy 21

Examples of Down syndrome in a Sentence

Recent Examples on the Web

The newborn, who had Down syndrome, was born on March 31 of that year at the Royal Alexandra Hospital in Paisley, the BBC reported. —Becca Longmire, People.com, 19 Feb. 2025

Neighbors said the matriarch of the family appeared to suffer dementia, while her adult daughter had Down syndrome. —John Annese, New York Daily News, 16 Feb. 2025

This proved beyond a doubt that Down syndrome is genetic. —Lorena Galliot, Scientific American, 5 Feb. 2025

The 37-year-old is the first actor with Down syndrome to ever lead an action movie, in the upcoming film Strait Undercover, produced by Fish & Crown Creative, according to the Today show. —Jen Juneau, People.com, 29 Jan. 2025

Word History

Etymology

J. L. H. Down †1896 English physician

First Known Use

1961, in the meaning defined above

Rhymes for Down syndrome

• acrosome
• aerodrome
• catacomb
• centrosome
• chromosome
• cytochrome
• hippodrome
• honeycomb
• liposome
• meerschaum
• metronome
• microtome

Kids Definition

Down syndrome

noun

ˈdau̇n-

variants or Down's syndrome

ˈdau̇n(z)-

: a genetic condition characterized especially by developmental delays, by distinctive physical traits (as short stature and upward slanting eyes), and by the presence of three chromosomes numbered 21 in human beings

Etymology

named for J.L.H. Down, 1828–1896, English doctor

Medical Definition

Down syndrome

noun

variants or Down's syndrome

: a congenital condition characterized especially by developmental delays, usually mild to moderate impairment in cognitive functioning, short stature, relatively small head, upward slanting eyes usually with epicanthal folds, flattened nasal bridge, broad hands with short fingers, decreased muscle tone, and by trisomy of the human chromosome numbered 21

called also Down, Down's, trisomy 21