noun (n)

• intentionally contemptuous behavior or attitude(noun.attribute)

  Synonym:
  rebelliousness
  

  source: wordnet30
• a hostile challenge(noun.communication)

  source: wordnet30
• a defiant act(noun.act)

  source: wordnet30
• The act of defying, putting in opposition, or provoking to combat; a challenge; a provocation; a summons to combat.(noun)

  source: webster1913