horizon

An horizon is the point on the earth where the sky and land seem to meet.

You've probably seen a beautiful landscape photo or been out in nature and noticed how far your eye can see. That's the horizon! It's like an invisible line that separates what you can see from everything beyond. But did you know that the word "horizon" isn't just about where the earth meets the sky? It's also used to talk about a limit or boundary of something, not just physically but also in other areas of life. For example, someone might say they're reaching the horizon of their knowledge on a particular subject, meaning they've learned as much as they can and are starting to get stuck. Or, when talking about goals, people might say they want to set their sights on the horizon, aiming high and working towards something new and challenging.