Unending means continuing forever without stopping or finishing. When you're stuck in the back seat on a long car trip and your little brother keeps asking “Are we there yet?” every five minutes, the drive can feel unending. When a teacher assigns what seems like an unending list of math problems, there are so many that you wonder if you'll ever reach the bottom of the page.

The word describes things that go on and on: the unending cycle of the seasons, the unending vastness of space, or the unending patience of a parent teaching a child to ride a bike for the hundredth time.

Sometimes unending describes actual infinity, like the unending decimal expansion of pi (3.14159...). Other times it simply means something feels like it will never stop, even though it eventually does. An unending argument between friends might finally conclude, and that supposedly unending homework does have a last problem, even if it doesn't feel that way while you're working through it.

The opposite of unending would be temporary, finite, or limited. Related words include endless, perpetual, and eternal, though unending puts special emphasis on the lack of any end point.