perimeter vs circumference

perimeter and circumference both are nouns.

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

As nouns, perimeter and circumference are synonyms defined as:

perimeter and circumference: the size of something as given by the distance around it

perimeter (noun)	circumference (noun)
the size of something as given by the distance around it	the size of something as given by the distance around it
the boundary line or the area immediately inside the boundary	the length of the closed curve of a circle
a line enclosing a plane areas	the boundary line encompassing an area or object