noun (n)

• someone who fights (or is fighting)(noun.person)

  Synonym:
  battler, belligerent, combatant, scrapper
  

  source: wordnet30
• a high-speed military or naval airplane designed to destroy enemy aircraft in the air(noun.artifact)

  Synonym:
  attack aircraft, fighter aircraft
  

  source: wordnet30
• someone who fights for a cause(noun.person)

  Synonym:
  champion, hero, paladin
  

  source: wordnet30
• One who fights; a combatant; a warrior.(noun)

  source: webster1913