noun (n)

• drowsiness and dullness manifested by yawning(noun.state)

  Synonym:
  oscitance
  

  source: wordnet30
• an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom(noun.act)

  Example:
  He apologized for his oscitancy.
  

  Synonym:
  oscitance, yawn, yawning
  

  source: wordnet30
• The act of gaping or yawning.(noun)

  source: webster1913