heterozygotePronunciation: /ˌhɛt(ə)rə(ʊ)ˈzʌɪgəʊt/Definition of heterozygote noun Genetics an individual having two different alleles of a particular gene or genes, and so giving rise to varying offspring. Compare with homozygote.Derivatives heterozygosity noun heterozygous adjective heterozygote in other Oxford dictionaries Definition of heterozygote in the US English dictionary