primogeniture

noun3

1. •
   The state of being the firstborn of the children of the same parents.
2. •
   The principle that the eldest child has an exclusive right of inheritance.

   • On these grounds, I contend the mere possession of large property, which is all that primogeniture insures, is by no means a sufficient and unobjectionable qualification for a legislator. — 1835
3. •
   An instance of such a right of inheritance, established by custom or law.

   • The American system of land tenures, the abolition of entails and primogenitures, and our methods of transfer of real estate, are all anti-English in their origin. — 1906