perimeter

noun

Etymology: From Latin perimetros, Ancient Greek περίμετρος (perímetros). Equivalent to peri- + meter.

1. The sum of the distance of all the lengths of the sides of an object.
2. The length of such a boundary.
3. The outer limits of an area.

   “In 1977, Papa Wemba decided to change the name of his housing tract, in the outskirts of Kinshasa, to Village Molokai,² of which he declared himself traditional chief. Then, within this perimeter, he advocated a clothing style that featured, among its distinctions, a beret, and that went along with a way of walking, talking, and behaving toward others.”

4. A fortified strip or boundary usually protecting a military position.
5. An instrument for determining the extent and shape of the field of vision.