border vs circumference

border and circumference both are nouns.

Word	Noun	Adjective	Verb	Adverb
border	Yes	No	Yes	No
circumference	Yes	No	No	No

As nouns, circumference is a hyponym of border; that is, circumference is a word with a more specific, narrower meaning than border:

Other hyponyms of border include circuit, fence line, property line, state boundary, state line.

border (noun)	circumference (noun)
a strip forming the outer edge of something	the size of something as given by the distance around it
a decorative recessed or relieved surface on an edge	the length of the closed curve of a circle
a line that indicates a boundary	the boundary line encompassing an area or object
the boundary of a surface
the boundary line or the area immediately inside the boundary

border (verb)	circumference (verb)
lie adjacent to another or share a boundary
extend on all sides of simultaneously; encircle
enclose in or as if in a frame
provide with a border or edge
form the boundary of; be contiguous to