"At all at all" is an informal expression used to emphasize that something is completely absent or has no relevance whatsoever. There are several synonyms for this phrase, including "not in the slightest," "not at all," "absolutely not," "by no means," and "in no way." Each of these expressions conveys a similar meaning to "at all at all," but with a more formal tone. Using these synonyms in place of the informal phrase can help improve the clarity and professionalism of your communication. So, the next time you need to express that something is entirely absent or irrelevant, consider using one of these synonyms instead of "at all at all".