The crossword solution for the term LEAVES NO DOUBT ABOUT is ASSURES, which is a 7-letter word. Assures is a verb that means to make certain or to guarantee something. It is often used in the context of providing assurance or security to someone, such as when a person assures another that something will be done. In this case, the phrase LEAVES NO DOUBT ABOUT is suggesting that the assurance provided is so strong that there is no doubt about it.