Customary is used to describe things that people usually do in a particular society or in particular circumstances.
双语例句
例： It is customary to offer a drink or a snack to guests.
给客人一杯饮料或一份小吃是一种习俗。
例： They interrupted the customary one minute's silence with jeers and shouts.
他们大声嘲笑叫喊，打破了惯例的一分钟肃静。