The Collaborative International Dictionary of English v.0.48:

Counselorship \Coun"sel*or*ship\ (koun"s?l-?r-sh?p), n.
   The function and rank or office of a counselor. --Bacon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

counselorship
    n 1: the position of counselor [syn: counselorship,
         counsellorship]