From Longman Dictionary of Contemporary EnglishY chromosomeY chro‧mo‧some /ˈwaɪ ˌkrəʊməsəʊm $ -ˌkroʊməsoʊm/ noun [countable] HBMthe part of a gene that makes someone a male instead of a female → X chromosome
Examples from the Corpus
Y chromosome• The fetus becomes male only when it both has a Y chromosome and is acted upon by androgenic hormones.• Consequently, a Cain gene on an X chromosome can safety kill the Y chromosome and not risk suicide.• In man, for instance, the genes that control gender are on the Y chromosome. 