A troll is a supernatural creature who is either very big or very small, ugly, and not very nice. You're most likely to read about a troll in a fairytale — perhaps trying to trick a beautiful princess into marrying him!
You’ve probably come across a troll before, maybe in The Lord of the Rings. As a verb, to troll means to wander around. You may have heard of a trolley, which is a vehicle that helps you travel around a city. The word troll more generally refers to anything that repeats itself regularly. You might troll a city, searching for a trolley, or you might troll parts of a song, repeating them one after the other to annoy your neighbors!