perimeter
n.
early 15c., "line around a figure or surface," from Latin perimetros, from Greek perimetron "circumference," from peri- "around" (see peri-) + metron "measure" (see meter, n.2). Military sense of "boundary of a defended position" is attested from 1943.
〔李〕[peri-=around 周；meter=measure 尺寸 ⇒“the measure around some area 某地周围的尺寸”→] n. the outer boundary of a figure or area 周围线，周长