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

One 2025 study indicated that facial recognition tools had higher error rates for adults with Down syndrome. —Janice Gassam Asare, Forbes.com, 6 Aug. 2025

One comment in particular stuck with her — a follower who shared that their neighbor’s child with Down syndrome had picked their flowers by mistake, prompting a heartfelt apology the next day. —Ashley Vega, People.com, 30 July 2025

Hardin, whose 13-year-old daughter has Down syndrome, has been pleased with the services and inclusive environment her Port Neches-area school district has provided Annie. —Keri Heath, Austin American Statesman, 30 July 2025

Hundreds have commented with overwhelming support and many others shared their own experiences with Down syndrome. —Daniella Gray, MSNBC Newsweek, 21 July 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