It basically means that someone makes a post in a thread to move it back to the top.
From the rules"
6. No Spam. Spamming is posting the same thing several times. "Bumping" (posting to move a thread up on the forum list) and cross-posting (posting the same thread in several forums) are examples of spam.
Hey SilkieChicken - question on this same subject if I may...
Sometimes a post doesn't get an answer because it's posted at a very slow time of day. I have found posts pages back that no one ever answered, I assume because it quickly got overridden by millions of other posts after it (Ok, maybe not quite millions
Is there a proper way to handle that since we can't bump a post but the poster still wants an answer but the post is too far back to been seen anymore?
You can bump it no problem if it's been a day or so. The issue with bumping occurs when someone does it every 10 or 20 minutes and you end up with a thread with 8 posts that all say "bump" within a few hours.
Posting something along the lines of "Hi, sorry I am not sure how to answer your question, but I'm sure someone will be along soon" is appropriate and contributes to the thread in that it brings it to the top in a more discrete way and shows the poster that someone is reading their thread.