See perimeter in Webster's New World Roget's A-Z Thesaurus II
noun
A line around a closed figure or area:
ambit, circuit, circumference, compass, periphery. See edge- (Chiefly Military)
A fairly narrow line or space forming a boundary:
border, borderline, brim, brink, edge, edging, fringe, margin, periphery, rim, verge. See edge
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