bourbon vs whiskey

bourbon and whiskey both are nouns.

Word	Noun	Adjective	Verb	Adverb
bourbon	Yes	No	No	No
whiskey	Yes	No	No	No

As nouns, whiskey is a hypernym of bourbon; that is, whiskey is a word with a broader meaning than bourbon:

bourbon: whiskey distilled from a mash of corn and malt and rye and aged in charred oak barrels
whiskey: a liquor made from fermented mash of grain

Other hypernyms of bourbon include whisky.

bourbon (noun)	whiskey (noun)
whiskey distilled from a mash of corn and malt and rye and aged in charred oak barrels	a liquor made from fermented mash of grain