from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The heir apparent to an ancient Celtic chief, elected during the chief's lifetime.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The heir presumptive to a Celtic clan.
from the GNU version of the Collaborative International Dictionary of English
- n. In Ireland, a lord or proprietor of a tract of land or of a castle, elected by a family, under the system of tanistry.
from The Century Dictionary and Cyclopedia
- n. The chief, or holder of the lands and honors, in certain Celtic races; sometimes, the chief's chosen successor. See tanistry.
Irish Gaelic tánaiste, second, tanist, from Old Irish tánaise.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Irish tánaiste ("second-in-command"). (Wiktionary)