Definition of: yawn

(yôn) v.i
1. To open the mouth wide, either voluntarily, as an animal seeking its prey, or involuntarily, with a long, full inspiration of the breath, usually as the result of drowsiness, fatigue, or boredom.
2. To be or stand wide open, especially as ready to engulf or receive something: A chasm yawned below.
—v.t.
3. To express or utter with a yawn.
—noun
1. A wide opening of the mouth, especially as from weariness.
2. The act of opening wide. [Prob, fusion of OE geonian yawn and gānian gape]
—yawn′er noun