Monogamous

Monogamy (/məˈnɒɡəmi/ mə-NOG-ə-mee) is a form of relationship in which an individual has only one partner during his or her lifetime or at any one time (serial monogamy), as compared to polygyny, polyandry, or polyamory. The term is also applied to the social behavior of some animals, referring to the state of having only one mate at any one time.

It is important to have a clear understanding of the nomenclature of monogamy because scientists use the term monogamy for different relationships. Biologists, biological anthropologists, and behavioral ecologists often use the term monogamy in the sense of sexual, if not genetic, monogamy. Modern biological researchers, using the theory of evolution, approach human monogamy as the same in human and non-human animal species. They postulate the following four aspects of monogamy:

When cultural or social anthropologists and other social scientists use the term monogamy, the meaning is social or marital monogamy. Marital monogamy may be further distinguished between:

Human monogamy's legal aspects are taught at faculties of law. There are also philosophical aspects in the field of interest of e.g. philosophical anthropology and philosophy of religion, as well as theological ones.

...
Wikipedia