The crossword solution for the term FELT BOOT is PAC, which stands for Polyacrylate-coated. Polyacrylate-coated felt boots are a type of footwear that is designed to be waterproof and provide insulation from cold temperatures. They are made from a combination of felt and polyacrylate, which is a synthetic material that is resistant to water and provides insulation. The felt boot is a popular choice for outdoor activities such as hiking, camping, and skiing.