tanistry

noun

A mode of tenure that prevailed among various Celtic tribes, according to which the tanist, or holder of honors and lands, held them only for life, and his successor was fixed by election.

noun

In Ireland, a tenure of family lands by which the proprietor had only a life estate, to which he was admitted by election.

noun

A form of tenure, in ancient Scotland and Ireland, whereby succession was passed to an elected member of the same extended family.