look under urban dictionary for troll and has a picture of japanfreak
One who purposely and deliberately (that purpose usually being self-amusement) starts an argument in a manner which attacks others on a forum without in any way listening to the arguments proposed by his or her peers. He will spark of such an argument via the use of ad hominem attacks (i.e. 'you're nothing but a fanboy' is a popular phrase) with no substance or relevence to back them up as well as straw man arguments, which he uses to simply avoid addressing the essence of the issue.
One who posts a deliberately provocative message to a
newsgroup or
message board with the intention of causing maximum disruption and argument.
1b. Noun
A person who, on a message forum of some type, attacks and
flames other members of the forum for any of a number of reasons such as rank, previous disagreements, sex, status, ect.
A troll usually flames threads without staying on topic, unlike a "Flamer" who flames a thread because he/she disagrees with the content of the thread.
1c. Noun
A member of an internet forum who continually harangues and harasses others. Someone with nothing worthwhile to add to a certain conversation, but rather continually
threadjacks or changes the subject, as well as thinks every member of the forum is talking about them and only them. Trolls often go by multiple names to circumvent getting banned.