1》 a series of events that are regularly repeated in the same order.
↘the period of time taken to complete a single such series.
2》 one complete sequence of changes associated with a recurring phenomenon such as an alternating current, wave, etc.
↘ Physics a ~ per second; one hertz.
↘ Ecology the movement of a simple substance through the soil, rocks, water, atmosphere, and living organisms of the earth: the carbon ~.
3》 a series of musical or literary works composed around a particular theme.
4》 a bi~.
↘a ride on a bi~: a 112-mile ~.
1》 ride a bi~.
2》 move in or follow a ~ of events.
ME: from OFr., from late L. cyclus , from Gk kuklos 'circle'.