haplodiploid Syllabification: (hap·lo·dip·loid)Pronunciation: /ˌhaplōˈdiploid/Definition of haplodiploid adjective Biology denoting or possessing a genetic system in which females develop from fertilized (diploid) eggs and males from unfertilized (haploid) ones. Derivatives haplodiploidy noun haplodiploid in other Oxford dictionaries Definition of haplodiploid in the British & World English dictionary