The term 'Securely Closed' can be broken down into two crossword solutions: 'SHUT' and 'Sealed'. 'SHUT' is a four-letter word that means to close something firmly, usually with a door or window. 'Sealed' is a six-letter word that means to make something airtight or watertight by closing it with a seal or adhesive. Together, these two words describe the act of securely closing something, making sure that it is completely closed and sealed off from the outside world.