materiality Syllabification: (ma·te·ri·al·i·ty)Pronunciation: /məˌti(ə)rēˈalitē/Definition of materiality noun (plural materialities) the quality or character of being material or composed of matter. chiefly Law the quality of being relevant or significant:the applicant must establish materiality on the balance of probabilitiesmateriality in other Oxford dictionaries Definition of materiality in the British & World English dictionary