Source : Webster's Revised Unabridged Dictionary (1913)

Campaign \Cam*paign"\, n. [F. campagne, It. campagna, fr. L.
   Campania the level country about Naples, fr. campus field.
   See {Camp}, and cf. {Champaign}, {Champagne}.]
   1. An open field; a large, open plain without considerable
      hills. See{Champaign}. --Grath.

   2. (Mil.) A connected series of military operations forming a
      distinct stage in a war; the time during which an army
      keeps the field. --Wilhelm.

   3. Political operations preceding an election; a canvass.
      [Cant, U. S.]

   4. (Metal.) The period during which a blast furnace is
      continuously in operation.

Campaign \Cam*paign"\, v. i.
   To serve in a campaign.

Source : WordNet®

campaign
     n 1: a race between candidates for elective office; "I managed
          his campaign for governor"; "he is raising money for a
          Senate run" [syn: {political campaign}, {run}]
     2: a series of actions advancing a principle or tending toward
        a particular end; "he supported populist campaigns"; "they
        worked in the cause of world peace"; "the team was ready
        for a drive toward the pennant"; "the movement to end
        slavery"; "contributed to the war effort" [syn: {cause}, {crusade},
         {drive}, {movement}, {effort}]
     3: several related operations aimed at achieving a particular
        goal (usually within geographical and temporal
        constraints) [syn: {military campaign}]
     4: an overland journey by hunters (especially in Africa) [syn:
        {hunting expedition}, {safari}]
     v 1: run, stand, or compete for an office or a position; "Who's
          running for treasurer this year?" [syn: {run}]
     2: exert oneself continuously, vigorously, or obtrusively to
        gain an end or engage in a crusade for a certain cause or
        person; be an advocate for; "The liberal party pushed for
        reforms"; "She is crusading for women's rights"; "The Dean
        is pushing for his favorite candidate" [syn: {crusade}, {fight},
         {press}, {push}, {agitate}]
     3: go on a campaign; go off to war [syn: {take the field}]