flier vs aviatrix

flier and aviatrix both are nouns.

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

As nouns, aviatrix is a hyponym of flier; that is, aviatrix is a word with a more specific, narrower meaning than flier:

Other hyponyms of flier include airwoman, aviatress, airplane pilot, pilot, airman.

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