flyer vs advert

flyer and advert both are nouns.

Word	Noun	Adjective	Verb	Adverb
flyer	Yes	No	No	No
advert	Yes	No	Yes	No

As nouns, advert is a hypernym of flyer; that is, advert is a word with a broader meaning than flyer:

flyer: an advertisement (usually printed on a page or in a leaflet) intended for wide distribution
advert: a public promotion of some product or service

Other hypernyms of flyer include ad, advertisement, advertising, advertizement, advertizing.

flyer (noun)	advert (noun)
an advertisement (usually printed on a page or in a leaflet) intended for wide distribution	a public promotion of some product or service
someone who travels by air
someone who operates an aircraft

flyer (verb)	advert (verb)
	make a more or less disguised reference to
	make reference to
	give heed (to)