matrimony

The story

1. Latin · derived frommātrimōnium“marriage, wedlock”
2. Old French · derived frommatremoine
3. English todaymatrimony

From Old French matremoine, from Latin mātrimōnium (“marriage, wedlock”), from mātri(s) (“mother”) + -mōnium (“obligation”). By surface analysis, matri- + -mony. Compare patrimony.