A troll is someone who posts mean or annoying comments online.
When we talk about trolls, most people think of them as those pesky internet users who love to argue and insult others on social media. They might post something hurtful or irrelevant just to stir up trouble. But the word "troll" actually has a broader meaning that's been around for longer than the internet. If you're walking along a river, a troll could be a mythical creature from old stories, often depicted as ugly and mischievous. It's this mythological sense of the word that might influence how people use it online – implying someone who's trying to stir up trouble or cause problems.
(originally Scandinavian mythology, now also European folklore and fantasy) a giant supernatural being, especially a grotesque humanoid creature living in caves or hills or under bridges.
