noun (n)

• the property of being flexible; easily bent or shaped(noun.attribute)

  Synonym:
  flexibleness
  Antonym:
  inflexibility, inflexibleness
  

  source: wordnet30
• the quality of being adaptable or variable(noun.attribute)

  Example:
  He enjoyed the flexibility of his working arrangement.
  

  Antonym:
  inflexibility, rigidity, rigidness
  

  source: wordnet30
• the trait of being easily persuaded(noun.attribute)

  Synonym:
  tractability, tractableness
  Antonym:
  intractability, intractableness
  

  source: wordnet30
• The state or quality of being flexible; flexibleness; pliancy; pliability; as, the flexibility of strips of hemlock, hickory, whalebone or metal, or of rays of light.(noun)

  source: webster1913