Meaning of a figure of speech wanted

[Unregistered]

What does the figure of speech "in the wings" mean and how does this meaning come about?

The context where I found it is a qoute by actor Harvey Keitel: "You either learn to overcome your fear or spend your life in the wings."

Thanks.

[Tdol]

If you are waiting to go on stage, you are in the wings, so it means that you're not actually performing, just waiting to do so.