tanist
/ˈtænɪst/
noun
- In historical Irish and Scottish Gaelic culture, the chosen successor or heir apparent to a chief or king, often elected from among the male relatives.
- In ancient Ireland, the tanist was usually the most capable adult male relative of the ruling chief.
- The tanist trained for years to take over leadership of the tribe.
- The clan elders selected the tanist to ensure a smooth transition of power when the chief grew old.