What does "bump" mean?

[Beaker74]

I know this may be a stupid question, but as I read these threads, people occasionally post a reply of "bump". Can anyone explain this to me? Thanks!

 

[circus slim]

As I understand it, when you post to a thread that has dropped off page one, or has gone to the bottom of the page, you are bumping it back up to the top.

Sometimes folks bump their own posts up if it gets lost in the mix here..

consider this a mini-bump!!