flapper vs fille

flapper and fille both are nouns.

Word	Noun	Adjective	Verb	Adverb
flapper	Yes	No	No	No
fille	Yes	No	No	No

As nouns, fille is a hypernym of flapper; that is, fille is a word with a broader meaning than flapper:

flapper: a young woman in the 1920s who flaunted her unconventional conduct and dress
fille: a young female

Other hypernyms of flapper include girl, miss, missy, young lady, young woman.

flapper (noun)	fille (noun)
a young woman in the 1920s who flaunted her unconventional conduct and dress	a young female