When a friend is browning or blacking due to alcohol and to his friend's unknowing knowledge slips away from a social scene, event, place, etc. to an unknown place to be found either (1) hours later at a random location or (2) asleep in a random location.
Person A: "Hey have you seen Chris?"
Person B: "No. He must be airhearting"
Person A: "Fuck. Why does he always have to airheart?"