girlfriend vs lady friend

girlfriend and lady friend both are nouns.

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

As nouns, girlfriend and lady friend are synonyms defined as:

girlfriend and lady friend: a girl or young woman with whom a man is romantically involved

Other synonyms of girlfriend include girl.

girlfriend (noun)	lady friend (noun)
a girl or young woman with whom a man is romantically involved	a girl or young woman with whom a man is romantically involved
any female friend