primogeniture
pri.mo.gen.i.ture \-'jen-*-.chu.(*)r, -i-ch*r, -*-.t(y)u.(*)r\ n [LL primogenitura, fr. L primus + genitura birth, fr. geni]tus, pp. 1: the state of being the firstborn of the children of the same parents 2: an exclusive right of inheritance belonging to the eldest son