The last tour by an aging musical act designed to gouge as much money from the public before the musical act retires. Typically involves exorbitant ticket and merchandise prices. Often a band will be missing at least one original member due to death or feuds with other band members that stretch back decades.
The decision to see a retourment concert is usually a choice between knowing it won't be value for money and being able to say that you saw them play live before they died.
Guy 1 'Did you hear that Black Sabbath is touring? Are you going to see them?'
Guy 2 'I’d like to but the tickets are so expensive.'
Guy 1 'True, and I hear Bill Ward isn’t playing drums. I bet the tour t-shirts will cost $50.'
Guy 2 'Let’s face it, it’s a total retourment.'