PHONY AS A SEVEN-POUND NOTE

(slang) very false indeed; not remotely genuine. A variation of the phrase phony as a three-dollar bill. Neither the seven-pound note nor the three-dollar bill have ever been in circulation as valid currency. —PDC Volume 8 Approved Glossary

a coined phrase meaning not remotely authentic or genuine; completely false. A pound is a monetary unit of the United Kingdom worth 100 pence. A seven-pound note has never been produced and thus if one existed it would obviously be counterfeit or phony. (slang) very false indeed; not remotely genuine. A variation of the phrase phony as a three-dollar bill. Neither the seven-pound note nor the three-dollar bill have ever been in circulation as valid currency.