noun (n)

• the quality of being capable -- physically or intellectually or legally(noun.attribute)

  Example:
  He worked to the limits of his capability.
  

  Synonym:
  capableness
  Antonym:
  incapability, incapableness
  

  source: wordnet30
• the susceptibility of something to a particular treatment(noun.state)

  Example:
  The capability of a metal to be fused.
  

  Synonym:
  capacity
  

  source: wordnet30
• an aptitude that may be developed(noun.cognition)

  Synonym:
  capableness, potentiality
  

  source: wordnet30
• The quality of being capable; capacity; capableness; esp. intellectual power or ability.(noun)

  source: webster1913