polygamy

Concise Oxford English Dictionary © 2008 Oxford University Press:
polygamy /pəˈlɪgəmi/

▶noun

• 1 the practice or custom of having more than one wife or husband at the same time.

• 2 Zoology a pattern of mating in which an animal has more than one mate.

• 3 Botany the condition of bearing some flowers with stamens only, some with pistils only, and some with both, on the same or different plants.

– derivatives
polygamist noun,
polygamous adjective,
polygamously adverb.

– origin C16: from Fr. polygamie, via late L. from Gk polugamia, from polugamos ‘often marrying’.