In Internet slang, a troll is a person who sows discord on the Internet by starting arguments or upsetting people, by posting inflammatory, extraneous, or off-topic messages in an online community (such as a newsgroup, forum, chat room, or blog) with the deliberate intent of provoking readers into an emotional response or of otherwise disrupting normal on-topic discussion. In my slang a troll is a turd. Just a heads up in case one lands on our forum.
This Urban Dictionary definition might help as well. Spoiler: Trolling Act of appearing on internet forums and boards with malicious intent. Trolling includes... Baiting people to flame at you. Putting the forum down and encouraging people to leave. Flaming Spamming Using several identities on a board to support your own arguments / stage pretend arguments. Generally being a dick on a power trip. Some trolls claim they actions benefit others. These trolls are also twats. Post1 did you see the way that guy was trolling? Post2 yep, he got banned. Post3 i just filled in another account. you guys are dicks. why did you ban me? im gonna spam the place up for that!!