[tan-ist, thaw-nist] 
| the successor apparent to a Celtic chief, usually the oldest or worthiest of his kin, chosen by election among the tribe during the chief's lifetime. |
| tan·ist (tān'ĭst, thô'nĭst) n. The heir apparent to an ancient Celtic chief, elected during the chief's lifetime. [Irish Gaelic tánaiste, second, tanist, from Old Irish tánaise; see sed- in Indo-European roots.] tan'ist·ry n. |