to move back; to draw back; to lessen; to subside; to resign; to retire
to take a step backward; to retreat a step; to back up
to feel awkward; to feel ashamed; to feel inferior; to feel shy (about doing something)
to back down; to back out (of a commitment or plan); to turn back; to withdraw; to retreat
(good) time to quit; (right) time to withdraw; time to pull out; time to retire; time to leave
moment to quit; way to quit