Source : Webster's Revised Unabridged Dictionary (1913)

Partisan \Par"ti*san\, n. [F. pertuisane, prob. fr. It.
   partigiana, influenced in French by OF. pertuisier to pierce.
   It was prob. so named as the weapon of some partisans, or
   party men. Cf. {Partisan} one of a corps of light troops.]
   A kind of halberd or pike; also, a truncheon; a staff.

         And make him with our pikes and partisans a grave.
                                                  --Shak.

Partisan \Par"ti*san\, n. [F., fr. It. partigiano. See {Party},
   and cf. {Partisan} a truncheon.] [Written also {partizan}.]
   1. An adherent to a party or faction; esp., one who is
      strongly and passionately devoted to a party or an
      interest. ``The violence of a partisan.'' --Macaulay.

            Both sides had their partisans in the colony.
                                                  --Jefferson.

   2. (Mil.)
      (a) The commander of a body of detached light troops
          engaged in making forays and harassing an enemy.
      (b) Any member of such a corps.

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.

Source : WordNet®

partisan
     adj 1: devoted to a cause or party [syn: {partizan}] [ant: {nonpartisan}]
     2: adhering or confined to a particular sect or denomination or
        party; "denominational prejudice" [syn: {denominational}]
     n 1: a fervent and even militant proponent of something [syn: {zealot},
           {drumbeater}]
     2: an ardent and enthusiastic supporter of some person or
        activity [syn: {enthusiast}, {partizan}]
     3: a pike with a long tapering double-edged blade with lateral
        projections; 16th and 17th centuries [syn: {partizan}]