[noun] [C] - the outer edge of an area of land or the border around itProtesters cut a hole in the perimeter fence.A river runs along one side of the field's perimeter.(specialized) The perimeter of a shape is the length of its outer edge.The perimeter of a square is four times the length of one side.
PERIMETER
Meaning of PERIMETER in English
Cambridge English vocab. Кембриджский английский словарь. 2012