Breadcrumb Home > Thesaurus > X Synonyms of xxy syndrome Find synonyms for: Noun 1. Klinefelter's syndrome, Klinefelter syndrome, XXY-syndrome, syndrome usage: syndrome in males that is characterized by small testes and long legs and enlarged breasts and reduced sperm production and mental retardation; a genetic defect in which an extra X chromosome (XXY) is present in the male WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. TrendingHere are the facts and trivia that people are buzzing about. The Book of 1 Corinthians: Summary Current Events This Week: June 2023 Languages Spoken in Each Country of the World Aesop's Fables: Aesop's Fables Milestones in Environmental Protection The 12 Labors of Hercules (In Order) ✖ Related Content Daily Word Quiz: hagiography Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language