male genitalia vs family jewels

male genitalia and family jewels both are nouns.

Word	Noun	Adjective	Verb	Adverb
male genitalia	Yes	No	No	No
family jewels	Yes	No	No	No

As nouns, male genitalia and family jewels are synonyms defined as:

Other synonyms of male genitalia include male genital organ, male genitals.

male genitalia (noun)	family jewels (noun)
external male sex organs	external male sex organs