ruler/ruːlər $ -lər/

n.

➊ a flat narrow piece of wood, plastic or metal, used for measuring or drawing straight lines

➋ a person who has the official power to control a country

n. [C]

➊ 直尺：This ruler shows inches and centimetres. 这把直尺上有英寸和厘米。

➋ 统治者，管理者：[ruler of sth] The ruler of the country was kind to his people. 这个国家的统治者善待他的民众。

构词rule + -er

音组-ler/-lər $ -lər/

roller; ruler; settler; thriller; traveler