coffee substitute vs java

coffee substitute and java both are nouns.

Word	Noun	Adjective	Verb	Adverb
coffee substitute	Yes	No	No	No
java	Yes	No	No	No

As nouns, java is a hypernym of coffee substitute; that is, java is a word with a broader meaning than coffee substitute:

coffee substitute: a drink resembling coffee that is sometimes substituted for it
java: a beverage consisting of an infusion of ground coffee beans

Other hypernyms of coffee substitute include coffee.

coffee substitute (noun)	java (noun)
a drink resembling coffee that is sometimes substituted for it	a beverage consisting of an infusion of ground coffee beans