noun (n)

• steadiness of mind under stress(noun.attribute)

  Example:
  He accepted their problems with composure and she with equanimity.
  

  Synonym:
  calm, calmness, equanimity
  Antonym:
  discomposure
  

  source: wordnet30
• The act of composing, or that which is composed; a composition.(noun)

  source: webster1913