Definify.com
Webster 1913 Edition
Birthright
Birth′rightˊ
,Noun.
Any right, privilege, or possession to which a person is entitled by birth, such as an estate descendible by law to an heir, or civil liberty under a free constitution; esp. the rights or inheritance of the first born.
Lest there be any . . . profane person, as Esau, who for one morsel of meat sold his
birthright
. Heb. xii. 16.
Webster 1828 Edition
Birthright
BIRTH'RIGHT
,Noun.
Esau, for a morsel, sold his birthright. Heb.12.
It may be used in the sense of primogeniture,or the privilege of the first born, but is applicable to any right which results from descent.