struggle
To try very hard to do something difficult.
Struggle means to try very hard to do something difficult, or to fight against something that's working against you. When you struggle with a challenging math problem, you're putting in serious effort even though it's not coming easily. When a plant struggles to grow in rocky soil, it's fighting to survive despite tough conditions.
The word captures that feeling of pushing against resistance. A swimmer might struggle against a strong current. A family might struggle financially, working hard to pay bills and save money. Your little brother might struggle to reach the top shelf. In each case, there's effort, difficulty, and determination mixed together.
Struggle can also be a noun: a student faces a struggle when learning a new language, or a country endures a struggle for independence. The word implies that the effort matters and that success isn't guaranteed, but also that trying is worthwhile.
Sometimes people say they're struggling when they really mean they're working hard at something important. A scientist might struggle for years to solve a problem before finally succeeding. That struggle, all that effort and persistence through difficulty, often makes the achievement meaningful. When something comes easily, we might enjoy it, but when we struggle for it and finally succeed, we remember it.