lady friend vs lover

lady friend and lover both are nouns.

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

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

Other hypernyms of lady friend include adult female, woman.

lady friend (noun)	lover (noun)
a girl or young woman with whom a man is romantically involved	a person who loves someone or is loved by someone
	an ardent follower and admirer
	a significant other to whom you are not related by marriage