lady friend vs woman

lady friend and woman both are nouns.

Word	Noun	Adjective	Verb	Adverb
lady friend	Yes	No	No	No
woman	Yes	No	No	No

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

Other hypernyms of lady friend include lover, adult female.

lady friend (noun)	woman (noun)
a girl or young woman with whom a man is romantically involved	women as a class
	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