/ Thesaurus / D Synonyms of down syndrome Find synonyms for: Noun1. mongolism, mongolianism, Down's syndrome, Down syndrome, trisomy 21, trisomy, birth defect, congenital anomaly, congenital defect, congenital disorder, congenital abnormalityusage: a congenital disorder caused by having an extra 21st chromosome; results in a flat face and short stature and mental retardationWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language