polygamy
noun /pəˈlɪɡəmi/
/pəˈlɪɡəmi/
[uncountable] (specialist)- the custom of having more than one wife at the same time
compare polyandry一夫多妻(制) 词源late 16th cent.: from French polygamie, via late Latin from Greek polugamia, from polugamos ‘often marrying’.