what does bump mean on facebook

On Facebook, "bump" is a term used to bring a post or message back to the top of a group or pages feed. This is done to increase engagement with the post and ensure that more members of the group or page see it in their feeds. The term "bump" comes from times when people would message over forums, and in order to keep threads at the top, people would comment "bump" on a thread to bump it up to the top. This practice has carried over onto todays social media sites.