Source : Webster's Revised Unabridged Dictionary (1913)

Partisan \Par"ti*san\, a. [Written also partizan.]
   1. Adherent to a party or faction; especially, having the
      character of blind, passionate, or unreasonable adherence
      to a party; as, blinded by partisan zeal.

   2. (Mil.) Serving as a partisan in a detached command; as, a
      partisan officer or corps.

   {Partisan ranger} (Mil.), a member of a partisan corps.