Cycle means a series of events or actions that repeat in the same order, over and over. The seasons follow a cycle: spring, summer, fall, winter, then back to spring again. Your sleep follows a daily cycle: you wake up, stay active during the day, get tired, sleep, and wake up again.

A cycle keeps going round like a wheel, with each part leading naturally to the next. The water cycle shows how water evaporates from oceans, forms clouds, falls as rain, flows back to the oceans, and starts again. Life cycles describe how living things are born, grow, reproduce, and eventually die, making room for new life to begin the cycle again.

Scientists use cycle to describe many natural patterns: the moon's phases cycle from new moon to full moon and back again. In everyday life, you might talk about a cycle of good and bad luck, or notice how your enthusiasm for a hobby goes through cycles of intense interest and cooling off.

People also use cycle as a verb: “The washing machine will cycle through rinse and spin.”