circular vs rounded

circular is a noun but rounded is not a noun.

Word	Noun	Adjective	Verb	Adverb
circular	Yes	Yes	No	No
rounded	No	Yes	No	No

circular (noun)	rounded (noun)
an advertisement (usually printed on a page or in a leaflet) intended for wide distribution

circular (adjective)	rounded (adjective)
having the shape or form of a circle	curving and somewhat round in shape rather than jagged
describing a circle; moving in a circle