The phrasal verb "stick in" has several synonyms that convey similar meanings. For example, to "persist," "linger," or "remain" can replace "stick in" when referring to an idea or thought that stays in one's mind. When discussing an object that is hard to remove or get rid of, synonyms such as "adhere," "cling," or "stick around" can be used. Further, when describing a person or situation that is causing discomfort or nuisance, alternatives like "bother," "irritate," and "grate" could be used. Understanding these various synonyms can help in choosing the appropriate word to convey the intended meaning effectively.