To underestimate means to guess that something is smaller, weaker, or less important than it actually is. When you underestimate how long your homework will take, you might think it'll only take fifteen minutes, then find yourself still working an hour later. When a team underestimates their opponent, they assume the game will be easy, then get surprised by how skilled the other players are.

People often underestimate challenges they haven't faced before. A hiker might underestimate how steep a mountain trail is, or a student might underestimate how much studying a subject requires. Sometimes people underestimate other people too. A new kid at school might seem quiet at first, but turns out to be brilliant at math or incredibly funny once you get to know them.

The opposite is overestimate, when you think something is bigger or harder than it really is. But underestimating carries a special risk: it can catch you unprepared. When you underestimate the difficulty of building a treehouse, you might run out of materials halfway through. When you underestimate the time needed to get ready for school, you end up rushing and forgetting things.

Being underestimated can actually work to your advantage. When others underestimate your abilities, you have the chance to surprise them with what you can really do.