long gone
1. Far away, having departed a relatively long time ago. The criminals are long gone by now. We just have to hope we can find a witness.
2. Totally depleted, having been consumed or used up a relatively long time ago. The food was long gone by the time I made it to the barbecue.
long gone
gone a long time ago; used up a long time ago. The ice cream and cake are long gone. You are simply too late for the refreshments.