to coin a phrase
From Longman Dictionary of Contemporary Englishto coin a phraseto coin a phrasespokenUSE something said in a joking way when you use a very common expression, to show that you know it is used a lot He’d thought the flight would never – to coin a phrase – get off the ground. → coinExamples from the Corpusto coin a phrase• I had to find out the hard way - to coin a phrase.• It is an odd sidelight, to coin a phrase, on road accidents.