ritual
noun [ C or U ] uk/ˈrɪtʃ.u.əl/ us/ˈrɪtʃ.u.əl/
C2 例行公事，老规矩;（尤指）仪式
a set of fixed actions and sometimes words performed regularly, especially as part of a ceremony
Coffee and the newspaper are part of my morning ritual. 喝咖啡和读报纸是我早晨必做的事情之一。
The birds were performing a complex mating ritual. 这些鸟在进行程序复杂的交配。