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