Definition of polygynously in English:
polygynously
adverb pəˈlɪdʒɪnəslipɒˈlɪdʒɪnəsli
1Cultural Anthropology. With more than one wife; in a polygynous context.
2Zoology. In a manner characterized by polygyny; with each male mating with several females.
Origin
1930s. From polygynous + -ly.