designating or of a form of marriage between a royal or noble person and a person of inferior rank, with the provision that neither the spouse of inferior rank nor the children of the marriage, if any, may lay claim to the rank or property of the other spouse
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'morganatic'< ML (matrimonium ad) morganaticam, (marriage with) morning gift < morganaticum, altered < OHG morgengeba, morning gift, gift given to the wife on the day after marriage (in lieu of any share
in the husband's property)