missy vs girl

missy and girl both are nouns.

Word	Noun	Adjective	Verb	Adverb
missy	Yes	No	No	No
girl	Yes	No	No	No

As nouns, missy and girl are synonyms defined as:

Other synonyms of missy include fille, miss, young lady, young woman.

missy (noun)	girl (noun)
a young female	a young female
	a girl or young woman with whom a man is romantically involved
	a youthful female person
	a friendly informal reference to a grown woman
	a female human offspring