The Collaborative International Dictionary
Polygamize
Polygamize \Po*lyg"a*mize\, v. i.
To practice polygamy; to marry several wives.
--Sylvester.
Coleridge.
Wiktionary
polygamize
vb. 1 (context intransitive English) To practice polygamy: to marry more than one wife or husband. 2 (context rare transitive English) To marry (multiple spouses).