The ruler of a country is the person who rules the country.
例句
...the former military ruler of Lesotho...莱索托的前军事统治者He was a weak-willed and indecisive ruler.他是一位意志薄弱、优柔寡断的统治者。
N-COUNT
尺;直尺
A ruler is a long flat piece of wood, metal, or plastic with straight edges marked in centimetres or inches. Rulers are used to measure things and to draw straight lines.
英汉词典释义
n.
尺, 直尺
Draw a line with a ruler.用尺子画一条线。
统治者, 支配者
A wise ruler is generous in victory.明智的统治者对待被击败的敌人是宽大的。
英英词典释义
Noun
1. measuring stick consisting of a strip of wood or metal or plastic with a straight edge that is used for drawing straight lines and measuring lengths