To troll is to insult or provoke, sometimes using subterfuge. An internet troll is someone who posts malicious comments online. The intention is to ridicule a group or individual.
Where does the word come from?
The etymology is complex. One possible source is the old French hunting term troller.
There is also a connection to a mythological Norse monster. In folklore, this describes ugly, magical cave-dwellers.
Trolling is also a fishing technique that involves dragging bait through the water.
Why did the word troll catch on online?
The Internet use of troll probably derives from a slang term used by US naval pilots in the 1970s - see here.
So trolls just insult people for fun?
Trolling can simply consist of crude abuse, but sometimes relies on deception. This can involve adopting a false identity to post ridiculous, provocative, threatening and/or abusive comments.
Are trolls just an unpleasant nuisance?
Concentrated malicious trolling can have a devastating impact, especially when personally directed at the vulnerable. Many have described the disorientating impact of social-media pile-on or concentrated personal attack.
