tanist Meaning, Definition & Usage

Ir. tanaiste, tanaise, second, the second person in rank, the presumptive or apparent heir to a prince.

In Ireland, a lord or proprietor of a tract of land or of a castle, elected by a family, under the system of tanistry.
This family [the O'Hanlons] were tanists of a large territory within the present county of Armagh. M. A. Lower.