female genital organ vs crotch

female genital organ and crotch both are nouns.

Word	Noun	Adjective	Verb	Adverb
female genital organ	Yes	No	No	No
crotch	Yes	No	No	No

As nouns, crotch is a hypernym of female genital organ; that is, crotch is a word with a broader meaning than female genital organ:

Other hypernyms of female genital organ include genital organ, genitalia, genitals, private parts, privates.

female genital organ (noun)	crotch (noun)
external female sex organs	the angle formed by the inner sides of the legs where they join the human trunk
	external sex organ
	the region of the angle formed by the junction of two branches