perimeter
noun [ C ] uk/pəˈrɪm.ɪ.tər/ us/pəˈrɪm.ə.t̬ɚ/
周边，边缘
the outer edge of an area of land or the border around it
Protesters cut a hole in the perimeter fence. 抗议者在周围的栅栏上砍出了一个洞。
A river runs along one side of the field's perimeter. 一条河沿这片田地的一侧流过。
mathematics specialized周，周长
the length of the outer edge of a shape