fruit juice vs potable

fruit juice and potable both are nouns.

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

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

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

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

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