noun (n)

• steadiness of mind under stress(noun.attribute)

  Synonym:
  calm, composure, equanimity
  Antonym:
  discomposure
  

  source: wordnet30
• an absence of strong winds or rain(noun.state)

  source: wordnet30
• a feeling of calm; an absence of agitation or excitement(noun.feeling)

  Antonym:
  agitation
  

  source: wordnet30
• The state of quality of being calm; quietness; tranquillity; self- repose.(noun)

  source: webster1913