stuffer vs circular

stuffer and circular both are nouns.

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

As nouns, circular is a hypernym of stuffer; that is, circular is a word with a broader meaning than stuffer:

stuffer: an advertising circular that is enclosed with other material and (usually) sent by mail
circular: an advertisement (usually printed on a page or in a leaflet) intended for wide distribution

Other hypernyms of stuffer include bill, broadsheet, broadside, flier, flyer, handbill, throwaway.

stuffer (noun)	circular (noun)
an advertising circular that is enclosed with other material and (usually) sent by mail	an advertisement (usually printed on a page or in a leaflet) intended for wide distribution
a craftsman who stuffs and mounts the skins of animals for display

stuffer (adjective)	circular (adjective)
	having the shape or form of a circle
	describing a circle; moving in a circle