The term 'PAY BY CREDIT CARD' can be summarized by the solution to the crossword clue 'CHARGE' which is a 6 letter word. This term refers to the process of paying for goods or services with a credit card, which is a type of payment card that allows the user to borrow funds from a financial institution in order to make purchases. Credit cards are typically issued by banks and other financial institutions and are used as an alternative to cash or checks.