perimeter

名词 perimeter:

1. the boundary line or the area immediately inside the boundary
   同义词：margin, border
2. a line enclosing a plane areas
3. the size of something as given by the distance around it
   同义词：circumference

1. The plane stalled, flipped over onto its back and crashed near the perimeter.
   飞机失速了，翻了一个跟头，坠毁在机场环形围栏附近。
2. Guards had been posted at several points around the perimeter.
   在环形防线上已布置了几处岗哨。
3. The barbed wire fence round the perimeter discouraged intruders.
   周围有铁丝网阻止了外人闯入。

pe.rim.e.ter

n.（名词）
Mathematics
【数学】
A closed curve bounding a plane area.
周界：围绕一平面域的封闭性边界
The length of such a boundary.
周长：此类边界的长度
The outer limits of an area.See Synonyms at circumference
一区域的外限参见 circumference
A fortified strip or boundary usually protecting a military position.
周界：筑有防御工事的地带或边界，常用以保护一军事地点

来源：
Middle English perimetre
中古英语 perimetre
from Latin perimetros
源自 拉丁语 perimetros
from Greek
源自 希腊语
peri- [peri-]
peri- [前缀，表示.周围.]
metron [measure] * see meter 2
metron [测量] *参见 meter2

【引伸】
per.imet.ric
per.imet.rically
adv.（副词）