from
The Collaborative International Dictionary of English v.0.48
Tanistry \Tan"ist*ry\, n. [See {Tanist}.]
In Ireland, a tenure of family lands by which the proprietor
had only a life estate, to which he was admitted by election.
[1913 Webster]
Note: The primitive intention seems to have been that the
inheritance should descend to the oldest or most worthy
of the blood and name of the deceased. This was, in
reality, giving it to the strongest; and the practice
often occasioned bloody feuds in families, for which
reason it was abolished under James I.
[1913 Webster]