noun (n)

• a feeling of intense annoyance caused by being tormented(noun.feeling)

  Example:
  So great was his harassment that he wanted to destroy his tormentors.
  

  Synonym:
  torment
  

  source: wordnet30
• the act of tormenting by continued persistent attacks and criticism(noun.act)

  Synonym:
  molestation
  

  source: wordnet30
• The act of harassing, or state of being harassed; worry; annoyance; anxiety.(noun)

  source: webster1913