To be lost means you don't know where you are or can't find your way to where you're trying to go. When hikers get lost in the woods, they've wandered off the trail and can't figure out which direction leads back to safety. When you're lost in a new city, the streets all look unfamiliar and you're not sure which way to turn.

The word also describes things you can no longer find. Your lost jacket might be somewhere in your house, or you might have left it at school. A lost dog has wandered away from home and can't find its way back.

Lost can mean defeated in a competition: your team lost the game, meaning the other side won.

The word sometimes describes being completely absorbed in something. When you're lost in a good book, you're so focused on the story that you barely notice what's happening around you. You might get lost in thought while staring out the window, your mind wandering through ideas and daydreams.

People also use lost to describe feeling confused or unable to understand something. If you're lost during a math lesson, the teacher's explanations aren't making sense and you can't follow along. Being lost in this way usually means you need more explanation to find your way back to understanding.