Posting the same thing to a second subreddit, ideally with a note saying so. For years the note was a title tag, [x-post from r/somewhere], which was the internet's way of admitting a repost before anyone could accuse you of one. Reddit built a native crosspost button in 2017 that keeps the original poster's name attached. Also the verb: to crosspost is to want two audiences and risk both. Elsewhere it means the same thing on any platform where a post can travel.
My first front-page post was a crosspost of someone else's photo with the tag done properly. I got the karma; they got a comment. Reddit in one transaction.
'x-post' and 'xpost' are the older title spellings and are still correct, not typos. The hyphen mostly died when the button arrived and the tag became redundant. Some subreddits ban crossposts outright; check the sidebar before doing anything on Reddit, which is also the rule for everything on Reddit.
Seen this week in r/mildlyinteresting: a photo crossposted from r/pics, with the first comment being the r/pics thread, and the second comment being someone crossposting it to r/all-tier circlejerk subs to mock both. Crosspost as a food chain.
The difference between a crosspost and a repost is a credit line. Crossposting says 'this was good, it belongs here too'; reposting says 'this was good, it is mine now'. The x-post tag was the honour system, and the 2017 button made honour automatic.
What does it mean? Write it the way you would say it out loud.
