Webster's Revised Unabridged Dictionary · 1913

Monogamy

Monogamy , noun

[Latin monogamia, Greek {not transcribed}: compare French monogamie.]

1.
Single marriage; marriage with but one person, husband or wife, at the same time; -- opposed to polygamy. Also, one marriage only during life; -- opposed to deuterogamy.
2.
(Zoology) State of being paired with a single mate.