"Tapers off" refers to the gradual decrease in something, and there are several synonyms that can be used to refer to this occurrence. One synonym is "ebbs," which connotes the receding of a tide or water level. Another word that can be used is "diminishes," which implies a steady reduction in size or intensity. "Fades" is another synonym that can be used to describe something gradually disappearing or declining. "Wanes" also works as a synonym for "tapers off," as it refers to the gradual decrease in a particular condition or quality. In summary, there are many words available to describe the process of something tapering off, and each word conveys a slightly different nuance or meaning.