noun (n)

• a sharp bitterness(noun.attribute)

  source: wordnet30
• a sharp sour taste(noun.attribute)

  Synonym:
  tartness
  

  source: wordnet30
• a rough and bitter manner(noun.attribute)

  Synonym:
  acrimony, bitterness, jaundice, tartness, thorniness
  

  source: wordnet30
• Sourness of taste, with bitterness and astringency, like that of unripe fruit.(noun)

  source: webster1913