The crossword solution for the term 'waterproof once more' is 'reseal, ' which is a six-letter word. Resealing is the process of making something waterproof again by applying a sealant or coating to it. This can be done to a variety of materials, such as wood, metal, and plastic, in order to protect them from water damage. Resealing is often used to repair items that have become damaged due to exposure to water, such as boats, roofs, and windows.