Forums can be complicated places with lots of terms you don't understand without explanation. So what does 'bump' mean when people type it in a forum?
In simple terms, it's used when there has been no reply to a post and as such the message has disappeared from the thread onto another page. The user replies to the post with 'bump' to get it back to the top.
It is known to stand for 'bring up my post' and alternatives are 'refresh' and '^'.