Entry 1 sense Webster, 1913 Apocynaceous · A·poc·y·na·ceous · IPA 01 a. Belonging to, or resembling, a family of plants, of which the dogbane (Apocynum) is the type. 1. Belonging to, or resembling, a family of plants, of which the dogbane (Apocynum) is the type.(Bot.)