The crossword solution for the term RADON LACKS IT is ODOR. Radon is a colorless, odorless, and tasteless gas that is naturally occurring in the environment. It is produced from the radioactive decay of radium and uranium, which are found in rocks and soil. Radon is a health hazard because it can accumulate in enclosed spaces and cause lung cancer. Therefore, it is important to be able to detect it, but since it has no ODOR, it is difficult to do so.