The term LEAK FIXER can be solved by two crossword solutions: PLUMBER (7 letters) and CAULK (5 letters). A plumber is a tradesperson who specializes in installing and maintaining systems used for water, sewage, and drainage. Plumbers are also responsible for repairing and installing fixtures such as sinks, toilets, and bathtubs. CAULK is a type of sealant used to fill gaps and cracks in various materials, including wood, metal, and concrete. It is often used to prevent water from entering a structure and to provide a waterproof seal. Both plumbers and CAULK are essential tools for fixing leaks.