What is another word for outer boundary?
Pronunciation: [ˈa͡ʊtə bˈa͡ʊndəɹi] (IPA) 
The term "outer boundary" refers to the limit or edge of something. There are several synonyms for this expression, including perimeter, circumference, boundary line, periphery, margin, rim, and verge. The perimeter is the measurement or length of the outer boundary. Circumference refers to the distance around the outer boundary, typically used for round shapes such as circles and cylinders. The boundary line is a straight or curved line that marks the outer edge of a defined area. The periphery is the external boundary or surface area of something. The margin is the outer edge of something. The rim is the outer edge of a circular object, and the verge is the edge or lip of something.
