fruit juice vs drinkable

fruit juice and drinkable both are nouns.

Word	Noun	Adjective	Verb	Adverb
fruit juice	Yes	No	No	No
drinkable	Yes	Yes	No	No

As nouns, drinkable is a hypernym of fruit juice; that is, drinkable is a word with a broader meaning than fruit juice:

Other hypernyms of fruit juice include beverage, drink, potable.

fruit juice (noun)	drinkable (noun)
drink produced by squeezing or crushing fruit	any liquid suitable for drinking

fruit juice (adjective)	drinkable (adjective)
	suitable for drinking