Source : Webster's Revised Unabridged Dictionary (1913)

Councilor \Coun"cil*or\ (koun"s?l-?r), n.
   A member of a council. [Written also {councillor}.]

   Note: The distinction between councilor, a member of a
         council, and counselor, one who gives councel, was not
         formerly made, but is now very generally recognized and
         observed.