bling bling vs jewelry

bling bling and jewelry both are nouns.

Word	Noun	Adjective	Verb	Adverb
bling bling	Yes	No	No	No
jewelry	Yes	No	No	No

As nouns, jewelry is a hypernym of bling bling; that is, jewelry is a word with a broader meaning than bling bling:

bling bling: flashy, ostentatious jewelry
jewelry: an adornment (as a bracelet or ring or necklace) made of precious metals and set with gems (or imitation gems)

Other hypernyms of bling bling include jewellery.

bling bling (noun)	jewelry (noun)
flashy, ostentatious jewelry	an adornment (as a bracelet or ring or necklace) made of precious metals and set with gems (or imitation gems)