The term 'SHUTTING UP' can be solved by two crossword solutions: SEALING (7 letters) and STILLING (8 letters). SEALING is the act of closing something securely, often with a wax or adhesive seal. This is commonly used to protect documents or packages from being opened without permission. STILLING is the process of making something quiet or still, usually through the use of a device such as a muffler or silencer. This is often used to reduce noise pollution or to make a machine quieter.