D defs.my
Entry 1 sense Webster, 1913

Birthright

/bẽrth'-rītˌ/ · Birth·right · IPA /ˈbɝθ.ɹaɪt/
01 n. 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 liber…
  1. 1.
    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.