To cease is to stop or end. Your gym teacher may have trained the class so well that all chattering will cease every time she blows her whistle.
Cease comes from the Old French cesser, which means "come to an end," "go away," "give up," or "yield." Although cease often appears in the past tense with "-ed," cease is common for talking about things as they come to an end. A dead plant has ceased living, and if you cease watering the rest of the plants, they will cease to exist too.