overdue UK /ˌəʊ.vəˈdju/US /ˌoʊ.vəɹˈdu/noun 2adjective 1forms 3 noun2 •A borrowed item (such as a library book) that has not been returned on time. •A payment or invoice that is past due. adjective1 •Late; especially, past a deadline or too late to fulfill a need.his library books were three days overdue; my car is overdue for an oil change; she finally left on a long overdue vacation formsoverdues · more overdue · most overdue