The term 'Green Card' refers to a United States Permanent Resident Card, which is a form of identification issued by the U.S. government to foreign nationals who have been granted permanent residency in the United States. The card is green in color, hence the name. The crossword solution for the term 'Green Card' is AMEX, which stands for American Express, a multinational financial services corporation. American Express offers a variety of credit cards, including the Green Card, which is a charge card that provides rewards and benefits to its users.