Entry 1 sense Webster, 1913 Polygyny /pəl-ĭj'-ən-ē/ · Po·lyg·y·ny · IPA /pəˈlɪd͡ʒ.ɪ.ni/ 01 n. The state or practice of having several wives at the same time; marriage to several wives. 1. The state or practice of having several wives at the same time; marriage to several wives.