Source : Webster's Revised Unabridged Dictionary (1913)

Defender \De*fend"er\, n. [Cf. {Fender}.]
   One who defends; one who maintains, supports, protects, or
   vindicates; a champion; an advocate; a vindicator.

         Provinces . . . left without their ancient and puissant
         defenders.                               --Motley.

Source : WordNet®

defender
     n 1: a person who cares for persons or property [syn: {guardian},
           {protector}, {shielder}]
     2: a fighter who holds out against attack [syn: {withstander}]