Primogeniture

n.	1.	The state of being the firstborn of the same parents; seniority by birth among children of the same family.
	2.	(Eng. Law) The exclusive right of inheritance which belongs to the eldest son. Thus in England the right of inheriting the estate of the father belongs to the eldest son, and in the royal family the eldest son of the sovereign is entitled to the throne by primogeniture. In exceptional cases, among the female children, the crown descends by right of primogeniture to the eldest daughter only and her issue.

Noun

1.

primogeniture - right of inheritance belongs exclusively to the eldest son

PRIMOGENITURE. The state of being first born the eldest.
     2. Formerly primogeniture gave a title in cases of descent to the oldest son in preference to the other children; this unjust distinction has been generally abolished in the United States.

aboriginality, age, ancien regime, ancientness, antiquity, atavism, bequeathal, bequest, birthright, borough-English, cobwebs of antiquity, coheirship, coparcenary, deanship, dust of ages, eld, elderliness, eldership, entail, gavelkind, great age, heirloom, heirship, hereditament, heritable, heritage, heritance, hoary age, hoary eld, incorporeal hereditament, inheritance, inveteracy, law of succession, legacy, line of succession, mode of succession, old age, old order, old style, oldness, patrimony, postremogeniture, primitiveness, primordialism, primordiality, reversion, senility, seniority, succession, ultimogeniture, venerableness