The act of tricking someone into watching Samwell's "What What (In the Butt)" video by sending them a link to the video, but claiming that it's a link to something they actually want to watch.
I'm going to Buttroll my friend Steve because I know how homophobic he is and it will really piss him off.
1) A bum troll is a medical condition by which the affected person becomes aroused by pulling on the anal hair until it stands straight making the shape of a trolls hair.