What is the meaning of yawn?

noun

• An involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom.
  • usage: "he could not suppress a yawn"; "the yawning in the audience told him it was time to stop"; "he apologized for his oscitancy"
  • synonyms: yawning, oscitance, oscitancy

verb

• Utter a yawn, as from lack of oxygen or when one is tired.
  • usage: "The child yawned during the long performance"
• Be wide open.
  • usage: "the deep gaping canyon"
  • synonyms: gape, yaw