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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Later pregnancies have a higher risk of complications such as miscarriage, high blood pressure and chromosomal abnormalities such as Down syndrome. Clara Harter, Los Angeles Times, 3 May 2025 Olivia was born Down syndrome, and Stephanie Asher said a portion of the money for the drink goes to the Down Syndrome Association of Connecticut. Sean Krofssik, Hartford Courant, 24 Apr. 2025 Following the passing of his wife, a devoted father learns to raise his son with Down syndrome as a single parent. Kate Erbland, IndieWire, 23 Apr. 2025 Donut Run benefits Down syndrome community GiGi’s Playhouse San Diego, a Down syndrome achievement center, will host its annual Donut Run 5K from 8 a.m. to noon April 27 at Crown Point Shores North, 700 Corona Oriente Road. Ut Community Press, San Diego Union-Tribune, 23 Apr. 2025 See All Example Sentences for Down syndrome

Word History

Etymology

J. L. H. Down †1896 English physician

First Known Use

1961, in the meaning defined above

Time Traveler
The first known use of Down syndrome was in 1961

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Cite this Entry

“Down syndrome.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Down%20syndrome. Accessed 8 May. 2025.

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

More from Merriam-Webster on Down syndrome

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