belle vs fille

belle and fille both are nouns.

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

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

belle: a young woman who is the most charming and beautiful of several rivals
fille: a young female

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

belle (noun)	fille (noun)
a young woman who is the most charming and beautiful of several rivals	a young female