The term 'USED PLASTIC' can be broken down into two crossword solutions: 'OWED' (4 letters) and 'CHARGED' (7 letters). 'OWED' is a verb meaning to be in debt or to have an obligation to pay something back. 'CHARGED' is a verb meaning to demand payment for something or to accuse someone of a crime. Together, these two words suggest that someone has used plastic, such as a credit card, to purchase something and now must pay the debt back.