The term 'USED GOOGLE WALLET, SAY' can be solved by the four letter word 'PAID'. Google Wallet is a digital payment system developed by Google that allows users to send money to each other and pay for purchases with their mobile devices. It was launched in 2011 and is available in the United States and the United Kingdom. With Google Wallet, users can store their credit cards, debit cards, loyalty cards, and gift cards in one place, making it easier to make payments. When someone uses Google Wallet to make a purchase, they simply enter their PIN or use their fingerprint to confirm the transaction.