Back away slowly, never leaving them out of your sight.

When everyone is asleep, climb out of your window, and walk away, do NOT look back.

back off = stand down or let it go

back away = move backwards away from someting; to put some distance between you and a thing by using backward movement

back out = move backwards out of something you're in or move backwards out of something by the same way you got in; extricate one's self

If you sold it, you buy it back. If you gifted it, you buy it back. If you had it taken away from you by the government you don't get it back.

Shove back means to push away. When the boy pushed him, he shoved back.