Could someone explain this word to me ? " Bump" when used in response to a post? i know that I have had a few to the head, but I don't think that's it     

They comment so there is a new response that brings the topic to the top of the list so people look at the post again and hopefully add something to answer the original question.

You need a special "Bumping" hammer  to do that!

It's shorter to type than, "bringing to the top".  Regrets that it bothered you!

Thanks, it didn't bother me at all, just looking for clarification!!

When there are a lot of comments and posts, BUMP gets the post more views. On some Facebook sales and auction sites the item can get lost when so many post new items.