the having of a plurality of wives or husbands at the same time; usually, the marriage of a man to more than one woman, or the practice of having several wives, at the same time; -- opposed to monogamy; as, the nations of the east practiced polygamy. see the note under bigamy, and cf. polyandry.-the state or habit of having more than one mate.-the condition or state of a plant which bears both perfect and unisexual flowers.