capstone
noun [ C ] uk/ˈkæp.stəʊn/ us/ˈkæp.stoʊn/
顶石，压顶石
a stone at the top of a wall or building
especially US顶点
someone's greatest achievement or the greatest part of something
This leadership position represents the capstone of my career. 获得这个领导的位置代表了我职业生涯的顶点。