noun (n)

• the quality of having the properties that are right for a specific purpose(noun.attribute)

  Example:
  An important requirement is suitability for long trips.
  

  Synonym:
  suitableness
  Antonym:
  ineptness, unsuitability, unsuitableness
  

  source: wordnet30
• The quality or state of being suitable; suitableness.(noun)

  source: webster1913