Definition: In Internet slang, a troll is someone who posts inflammatory, extraneous, or off-topic messages in an online community, such as an online discussion forum, chat room or blog, with the primary intent of provoking other users into a desired emotional response or of otherwise disrupting normal on-topic discussion. In addition to the offending poster, the noun “troll” can also refer to the provocative message itself, as in that was an excellent troll you posted. While the term troll and its associated action, trolling, are primarily associated with Internet discourse, media attention in recent years has made such labels highly subjective, with trolling being used to describe many intentionally provocative actions outside of an online context.

History of "Troll": The contemporary use of the term is alleged to have first appeared on the Internet in the late 1980s, but the earliest known example is from 1992. It is thought to be a truncation of the phrase trolling for suckers. That phrase is itself derived from the fishing technique of slowly dragging a lure or baited hook from a moving boat, waiting for fish to strike, a technique known as trolling. The word also evokes the trolls portrayed in Scandinavian folklore and children's tales, as they are often creatures bent on mischief and wickedness. The verb "troll" originates from Old French "troller", a hunting term. The noun "troll", however, comes from the Old Norse word for a mythological monster. The most likely derivation of the word troll can be found in the phrase "trolling for newbies", popularized in the early 1990s in the Usenet group, alt.folklore.urban (AFU). Commonly, what is meant is a relatively gentle inside joke by veteran users, presenting questions or topics that had been so overdone that only a new user would respond to them earnestly. For example, a veteran of the group might make a post on the common misconception that glass flows over time. Long-time readers would both recognize the poster's name and know that the topic had been done to death already, but new subscribers to the group would not realize, and would thus respond. These types of trolls served as a practice to identify group insiders. This definition of trolling, considerably narrower than the modern understanding of the term, was considered a positive contribution. One of the most notorious AFU trollers, Snopes, went on to create his eponymous urban folklore website.
By the late 1990s, alt.folklore.urban had such heavy traffic and participation that trolling of this sort was frowned upon. Others expanded the term to include the practice of playing a seriously misinformed or deluded user, even in newsgroups where one was not a regular; these were often attempts at humor rather than provocation. In such contexts, the noun troll usually referred to an act of trolling, rather than to the author.

Other Languages: Most languages have adopted the English word "troll" to refer to Internet trolls. In Japanese, arashi (あらし) means "laying waste" and can also be used to refer to simple spamming. In Danish, "Trold" means "Troll" (the mythologic character, a kind of monster). In Korean, nak-si (낚시) means "fishing", and is used to refer to Internet trolling attempts, as well as purposefully misleading post titles. A person who recognizes the troll after having responded (or, in case of a post title nak-si, having read the actual post) would often refer to himself as a caught fish. In Thai, the term "krean" (เกรียน) has been adopted to address Internet trolls. The term literally refers to a closely cropped hairstyle worn by most school boys in Thailand, thus equating the emotional and egoistic immaturity of Internet trolls to that of a school boy. The term "tob krean" (ตบเกรียน), or slapping a cropped head, refers to the act of posting intellectual replies to refute and cause the messages of Internet trolls to be unintelligent.