The term SNAIL'S PROTECTION can be solved by the crossword solution SHELL, which is a five-letter word. A snail's SHELL is a hard protective covering that is made of calcium carbonate and is secreted by the snail's mantle. The SHELL provides protection from predators and environmental hazards, such as desiccation, and helps the snail to retain moisture. It also serves as a storage area for nutrients and waste products.