yawn

To open the mouth wide with a deep inhalation, usually involuntarily from drowsiness, fatigue, or boredom.

To open wide; gape.

To utter wearily, as while yawning.

The act of yawning.

One that provokes yawns; a bore.

The act of gaping or opening wide.

An involuntary opening of the mouth from drowsiness; oscitation. See yawning.

An opening; a chasm.

To gape; open; stand wide.

Specifically