So as to face in the opposite way; from front to back or back to front; half round. Also (rarely): around by a small angle; to one side, aside, away.

So as to face a different or opposite way; so as to change or reverse direction. Chiefly with turn.

So as to face a different or opposite way; so as to change or reverse direction. Frequently with turn.

So as to face a different or opposite way; so as to change or reverse direction; in the opposite direction. Frequently with turn (see also the verb).