noun (n)

• the feeling caused by agreeable stimuli; one pole of a continuum of states of feeling(noun.feeling)

  source: wordnet30
• the quality of giving pleasure(noun.attribute)

  Example:
  The pleasantness of a cool breeze on a hot summer day.
  

  Synonym:
  sweetness
  Antonym:
  unpleasantness
  

  source: wordnet30
• The state or quality of being pleasant.(noun)

  source: webster1913