The word "repost" is commonly used when referring to sharing an existing post on social media or an online platform. However, there are several synonyms that can be used interchangeably. One such synonym is "re-share," which means to share something again. Another synonym is "retweet," which is specific to sharing a tweet on Twitter. "Reblog" is a synonym often used in the blogging community when sharing someone else's blog post. "Rebroadcast" is a synonym typically used in broadcast media when replaying a previously aired program. Lastly, "recirculate" can be used when referring to sharing or circulating something again. Overall, there are several synonyms for "repost" depending on the context in which it is used.