histocompatibility Syllabification: (his·to·com·pat·i·bil·i·ty)Pronunciation: /ˌhistōkəmˌpatəˈbilitē/Definition of histocompatibility noun Medicine compatibility between the tissues of different individuals, so that one accepts a graft from the other without having an immune reaction. histocompatibility in other Oxford dictionaries Definition of histocompatibility in the British & World English dictionary