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

With hands bound together with packing tape, a high school student with Down syndrome was forced to walk around a classroom for hours as a special education teacher cursed at him, Texas police said. —Kate Linderman, Fort Worth Star-Telegram, 2 Apr. 2025

After her children grow up, including her son Emmett, who has Down syndrome, Paige decides to write about the challenges of motherhood in a memoir. —Carly Tagen-Dye, People.com, 28 Mar. 2025

For decades, prenatal testing for Down syndrome and other chromosomal conditions had fallen into two categories: invasive biopsies using a needle to collect fetal cells from the amniotic fluid or the placenta, or biomarker testing via a simple blood draw from the pregnant person. —Laura Hercher, Scientific American, 24 Mar. 2025

Jake Burger is using his platform to share the joys and challenges of raising a baby girl with Down syndrome. —Ryan Brennan, Miami Herald, 23 Mar. 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