noun (n)

• a sensitivity that is keen and highly developed(noun.cognition)

  Example:
  Dogs have a remarkable acuteness of smell.
  

  source: wordnet30
• a quick and penetrating intelligence(noun.cognition)

  Example:
  He argued with great acuteness.
  

  Synonym:
  acuity, keenness, sharpness
  

  source: wordnet30
• the quality of having a sharp edge or point(noun.attribute)

  Antonym:
  obtuseness
  

  source: wordnet30
• The quality of being acute or pointed; sharpness; as, the acuteness of an angle.(noun)

  source: webster1913