This word is posted to a topic tread if the poster wants to re-callattention to the thread.
Most regular forum users typically hit "new posts" to read new posts since their last visit, so an old topic will be lost to these readers. Bumping a topic is essentially "bumping" it back into view for most readers.
'To Bump' something is to snort a drug. Usually Ketamine but can be speed or coke.
To have 'A Bump' is to snort a small, conveniant amount of the above substances. Usually on the corner of a credit card or a small line snorted from your hand or otherwise.
At home: "Let's 'bump' a some fat line's of K and get into a K-Hole."
At a Club: "Here, have 'a bump' offa this bankcard."