nanny vs woman

nanny and woman both are nouns.

Word	Noun	Adjective	Verb	Adverb
nanny	Yes	No	No	No
woman	Yes	No	No	No

As nouns, woman is a hypernym of nanny; that is, woman is a word with a broader meaning than nanny:

Other hypernyms of nanny include keeper, adult female.

nanny (noun)	woman (noun)
female goat	women as a class
a woman who is the custodian of children	an adult female person (as opposed to a man)
	a female person who plays a significant role (wife or mistress or girlfriend) in the life of a particular man