morganatic: [18] A morganatic marriage is one between people of different social status, in which the rank and entitlements of the higherstatus partner are not shared by the lower or their offspring. The word morganatic is a survival of an ancient Germanic marriage custom. On the morning after the wedding night, after the marriage had been consummated, the husband gave the wife a symbolic gift, which removed any further legal claim the wife or their children might have on his possessions.
The term for this useful gift was *morgangeba, a compound formed from *morgan (ancestor of English morning) and *geba (a noun formed from the same base as produced English give). The word was adopted into medieval Latin as morganaticus, from which (via either French or German) English got morganatic. => morning, give[morganatic etymology, morganatic origin, 英语词源]