triploid Syllabification: (trip·loid)Pronunciation: /ˈtriploid/ GeneticsDefinition of triploid adjective (of a cell or nucleus) containing three homologous sets of chromosomes. (of an organism or species) composed of triploid cells. noun a triploid organism, variety, or species. Derivatives triploidyPronunciation: /ˈtriˌploidē/ noun triploid in other Oxford dictionaries Definition of triploid in the British & World English dictionary