The term 'CLOSE FOR SECURITY' can be summarized by the solution to the crossword clue 'SEAL' which is a four letter word. A SEAL is a device or material that is used to close off an area or object for security purposes. Seals are often used to protect documents, packages, and other items from being tampered with or opened without authorization. Seals can also be used to secure doors, windows, and other openings to prevent unauthorized access.