Definition: In law, a primogenitor is someone who has more than one child with another person. Primogeniture refers to the practice of dividing an estate among the children based on their birth order or age. In this context, a "primogenitor" would be a person who has more than one child with another person at birth, and they are entitled to inherit from that person's estate. For example, if two people were married and had four children, each of whom was born before the