Y

vb. To open the mouth involuntarily through drowsiness, dullness, or fatigue; to gape; to oscitate. To open wide; to gape, as if to allow the entrance or exit of anything. To open the mouth, or to gape, through surprise or bewilderment. To be eager; to desire to swallow anything; to express desire by yawning; as, to yawn for fat livings.

 - n. An involuntary act, excited by drowsiness, etc., consisting of a deep and long inspiration following several successive attempts at inspiration, the mouth being wide open. The act of opening wide, or of gaping. A chasm, mouth, or passageway.