1. The end of time. Although you don't have to pay for medical care in this country, you'll sometimes be waiting until kingdom come to receive elective treatment. My wife and her sister will talk on the phone until kingdom come if nothing interrupts them!

2. Heaven; the afterlife. Often used humorously, the phrase is taken from the Lord's Prayer. You all need to be very careful not to blow us to kingdom come while doing this experiment in the lab.