Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Yawn
Medically reviewed by Min Clinic Staff | Updated: January 2026
Yawn: Involuntary opening of the mouth, accompanied by slowly breathing inward and then outward. Repeated yawning can be a sign of drowsiness, boredom, or depression. The yawn helps to open tiny air sacs (alveoli) in the lungs that can collapse during shallow breathing.