noun (n)

• unfriendly behavior that causes anger or resentment(noun.act)

  Synonym:
  aggravation, irritation
  

  source: wordnet30
• something that incites or provokes; a means of arousing or stirring to action(noun.motive)

  Synonym:
  incitation, incitement
  

  source: wordnet30
• needed encouragement(noun.communication)

  Example:
  The result was a provocation of vigorous investigation.
  

  Synonym:
  incitement
  

  source: wordnet30
• The act of provoking, or causing vexation or, anger.(noun)

  source: webster1913