To allow something to happen or unfold without interfering or taking part an active part in it. You may not be directly responsible, but you sat back and let John squander the company's money. In my eye, that makes you just as culpable. We all get older, but I refuse to just sit back and let it happen to me—I want to get out into the world and experience as much as I possibly can in the time I have left! Instead of just sitting back and letting your talents go to waste in this dead-end job, why don't you strike out on your own?