1.
If you ~, you move or stay slightly behind a person or group, usually because you are nervous about something.
I saw him step forward momentarily but then ~, nervously massaging his hands.
PHRASAL VERB: V P
2.
If a person or organization hangs back, they do not do something immediately.
They will then ~ on closing the deal...
Even his closest advisers believe he should ~ no longer.
PHRASAL VERB: V P on n, V P