1 definition by Sir Hatter

A form of YouTube spam where YouTube users, typically idiotic women with oversized breasts, decide to upload a video entitled "RE: Videoname" and post it as a video reply. As a result, they manage to fill the "Related Videos" section of YouTube with a plethora of breasts, as opposed to actual content that's actually related to the current video.

Most YouTube users view Reply Girls as a nuisance. There are some people who enjoy the Reply Girls, but all they look at are the thumbnails with their exposed cleavage, leave a stupid-ass comment, and then leave the video.
*Reply Girl creates a reply and adds it to video response*

*Video responses for reply girls appear in the side bar*

YouTube User: BEWBS!!!!1!!1!1---------------------->>>>
by Sir Hatter February 28, 2012
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