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mo•nog•a•my
Etymology: French monogamie, from Late Latin monogamia, from Greek, from monogamos monogamous, from mon- + gamos marriage, from gamein to marry
Date: 1612
1 archaic : the practice of marrying only once during a lifetime
2 : the state or custom of being married to one person at a time
3 : the condition or practice of having a single mate during a period of time
— mo•nog•a•mous \mə-ˈnä-gə-məs\ also mono•gam•ic \ˌmä-nə-ˈga-mik\ adjective
— mo•nog•a•mous•ly adverb

Don Firth