compass plane vs circular plane

compass plane and circular plane both are nouns.

Word	Noun	Adjective	Verb	Adverb
compass plane	Yes	No	No	No
circular plane	Yes	No	No	No

As nouns, compass plane and circular plane are synonyms defined as:

compass plane and circular plane: a plane with a flexible face that can plane concave or convex surfaces

compass plane (noun)	circular plane (noun)
a plane with a flexible face that can plane concave or convex surfaces	a plane with a flexible face that can plane concave or convex surfaces