Breadcrumb Home > Dictionary > Index X X chromosome: Meaning and Definition of Find definitions for: X chromosome Pronunciation: [key] — Genetics. Genetics. a sex chromosome of humans and most mammals that determines femaleness when paired with anotherchromosome and that occurs singly in males. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. xc xcl TrendingHere are the facts and trivia that people are buzzing about. Star Trek: First Contact Current Events This Week: September 2023 Countries with the Highest Literacy Rates 50 Funniest "Futurama" Quotes Dangerous Animals: Scorpions, Bears, and Poison-Dart Tree Frogs State Capitals and Largest Cities (& Some Common Questions) ✖ Related Content Daily Word Quiz: camenae Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language