be reluctant to proceed, hesitate; drag or fall behind others who are proceeding
If a person or organization hangs back, they do not do something immediately. They will then hang back on closing the deal Even his closest advisers believe he should hang back no longer
If you hang back, 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 hang back, nervously massaging his hands