Polygamy is the practice, or the system, of being married to more than one person at the same time. History books, law reports, and religion classes use it. In most places English law allows only one spouse, so the word often appears when people discuss a country, a faith, or a group whose custom is different.

Polygamy is the practice, or the systemPolygamy指的是這種做法或制度, of being married to more than one person at the same time同時和一個以上的人結婚。History books, law reports, and religion classes use it歷史書、法律報告和宗教課程會用到這個字。In most places在大部分地方 English law allows only one spouse英文法律只允許一位配偶, so the word often appears所以這個字就常常出現 when people discuss a country, a faith, or a group whose custom is different當大家在討論某個國家、某個信仰，或風俗不同的某個群體時。

Though actually, everyday talk and even some textbooks say polygamy when they only mean one husband with several wives. The wider English word also includes the much rarer case of one wife with several husbands.

Though actually不過其實, everyday talk and even some textbooks日常說話裡，甚至有些教科書 say polygamy會把polygamy拿來 when they only mean one husband with several wives只指一夫多妻。The wider English word also includes英文裡更廣義的用法，也包含 the much rarer case of one wife with several husbands比較罕見的一妻多夫。

It is not the same as an affair, and it is not the same as having several romantic partners without marriage. Formal English.

It is not the same as an affair它跟外遇不一樣, and it is not the same as having several romantic partners without marriage也跟沒有婚姻關係、同時有好幾個戀愛對象不一樣。Formal English是正式英文。