Yawn
Definition 1 of 4
Pro Tip 1/2
Contagious Action
Seeing or hearing someone yawn often makes others feel like yawning too. As soon as he yawned, the whole room started to yawn one after another.
Pro Tip 2/2
Politeness
It's considered impolite to yawn openly in some cultures, especially without covering your mouth. When I yawned without covering my mouth, my mother reminded me of my manners.