an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom; "he could not suppress a yawn"; "the yawning in the audience told him it was time to stop"; "he apologized for his oscitancy"
口を大きく開けて、無意識のうちに息を吸うこと
yawn
utter a yawn, as from lack of oxygen or when one is tired; "The child yawned during the long performance"