To renew means to make something fresh, strong, or valid again. When you renew a library book, you extend the time you're allowed to keep it. When your family renews a magazine subscription, you arrange to keep receiving it for another year.

The word often describes restoring something that has worn down or expired. After a good night's sleep, you wake up feeling renewed, with your energy restored. A long vacation can renew your enthusiasm for school. Cities sometimes renew old neighborhoods by fixing up buildings and adding parks, a process called urban renewal.

Renewable resources are things that naturally replenish themselves, like sunlight, wind, or trees that can be replanted. These contrast with non-renewable resources like coal or oil, which take millions of years to form and will eventually run out.

The word carries a sense of continuation rather than starting from scratch. When you renew something, you're not creating it from scratch: you're extending or refreshing what already exists. A commitment to renew your effort in math class means you're going to try harder again, bringing back the determination you may have let slip.