flier vs aviator

flier and aviator both are nouns.

Word	Noun	Adjective	Verb	Adverb
flier	Yes	No	No	No
aviator	Yes	No	No	No

As nouns, flier and aviator are synonyms defined as:

Other synonyms of flier include aeronaut, flyer.

flier (noun)	aviator (noun)
an advertisement (usually printed on a page or in a leaflet) intended for wide distribution	someone who operates an aircraft
someone who travels by air
someone who operates an aircraft