2. Utter a yawn; as from a lack of oxygen or when tired or bored.
3. To open the mouth wide with a deep inhalation, usually involuntarily because of drowsiness, fatigue, or boredom.
4. To open wide; to gape: "The chasm yawned at our feet."
5. To utter wearily, while or as if while yawning: "He yawned his disapproval about plans for the weekend trip."
6. Etymology: Yawn ultimately goes back to the Indo-European base ghei-, ghi-, which also produced Greek khaskein, "gape"; a close relative of English chasm and Latin hiare, "gape, yawn"; source of English hiatus.
Involuntary opening of the mouth, which is often caused by suggestion. Yawning is characterized by breathing first inward, then outward. Repeated yawning is often a sign of drowsiness. It may also sometimes be a sign of depression.
While Bill's mother was sitting under the awning, she found herself in a yawning condition because the chair was so comfortable and the day was pleasantly warm.