Source : Webster's Revised Unabridged Dictionary (1913)

Warfare \War"fare`\, n. [War + OE. fare a journey, a passage,
   course, AS. faru. See {Fare}, n.]
   1. Military service; military life; contest carried on by
      enemies; hostilities; war.

            The Philistines gathered their armies together for
            warfare, to fight with Israel.        --I Sam.
                                                  xxviii. 1.

            This day from battle rest; Faithful hath been your
            warfare.                              --Milton.

   2. Contest; struggle.

            The weapons of our warfare are not carnal. --2 Cor.
                                                  x. 4.

Warfare \War"fare`\, v. i.
   To lead a military life; to carry on continual wars.
   --Camden.

Source : WordNet®

warfare
     n 1: the waging of armed conflict against an enemy; "thousands of
          people were killed in the war" [syn: {war}]
     2: an active struggle between competing entities; "a price
        war"; "a war of wits"; "diplomatic warfare" [syn: {war}]