Merriam-Webster Collegiate Dictionary - monogamy

 noun  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 ~ is common among birds  • monogamous also monogamic adjective  • monogamously adverb