tier

名词 tier:

1. a relative position or degree of value in a graded group
   同义词：grade, level
2. any one of two or more competitors who tie one another
3. a worker who ties something
   同义词：tier up
4. something that is used for tying
5. one of two or more layers one atop another

1. An oval or a round structure having tiers of seats rising gradually outward from an open space or arena at the center.
   圆形露天剧场蛋形或圆形建筑，在露天的中央场地周围有逐渐向外斜上升的阶梯式座位
2. A stadium with four tiers of seats.
   一个有四层座位的体育馆