(每日一词）cyclical

Cyclical  /ˈsɪk.lɪ.kəl/ adj. 周期的

meaning: cyclical events happen in a particular order, one following the other, and are often repeated 

词根：cycl- 圆圈bicycle 

后缀：-ic, -al 形容词后缀

e.g. Changes in the economy have followed a cyclical pattern. 经济呈周期性变化。