aqua vitae vs John Barleycorn

aqua vitae and John Barleycorn both are nouns.

Word	Noun	Adjective	Verb	Adverb
aqua vitae	Yes	No	No	No
John Barleycorn	Yes	No	No	No

As nouns, John Barleycorn is a hypernym of aqua vitae; that is, John Barleycorn is a word with a broader meaning than aqua vitae:

aqua vitae: strong distilled liquor or brandy
John Barleycorn: an alcoholic beverage that is distilled rather than fermented

Other hypernyms of aqua vitae include booze, hard drink, hard liquor, liquor, spirits, strong drink.

aqua vitae (noun)	John Barleycorn (noun)
strong distilled liquor or brandy	an alcoholic beverage that is distilled rather than fermented