noun (n)

• appropriate conduct; doing the right thing(noun.attribute)

  Synonym:
  rightness
  Antonym:
  inappropriateness, wrongness
  

  source: wordnet30
• the quality of being specially suitable(noun.attribute)

  Antonym:
  inappropriateness, unworthiness
  

  source: wordnet30
• The state or quality of being appropriate; peculiar fitness.(noun)

  source: webster1913