Polygyny

Polygyny (from neo-Greek πολυγυνία from πολύ poly "many", and γυνή gyny "woman or wife") is a mating system involving one male and two or more females, or a form of marriage in which a man has two or more wives at the same time. In countries where the practice is illegal, the man is referred to as a bigamist or a polygamist. It is distinguished from relationships where a man has a sexual partner outside marriage, such as a concubine, casual sexual partner, paramour, cohabits with a married woman or other culturally but not legally recognized secondary partner. Polygyny is the most common form of polygamy; the much rarer practice of polyandry is the form of marriage in which one woman has two or more husbands at the same time, usually among brothers or males of the same family.