malt whiskey vs malt whisky

malt whiskey and malt whisky both are nouns.

Word	Noun	Adjective	Verb	Adverb
malt whiskey	Yes	No	No	No
malt whisky	Yes	No	No	No

As nouns, malt whiskey and malt whisky are synonyms defined as:

malt whiskey and malt whisky: whiskey distilled in Scotland; especially whiskey made from malted barley in a pot still

Other synonyms of malt whiskey include Scotch, Scotch malt whiskey, Scotch malt whisky, Scotch whiskey, Scotch whisky.

malt whiskey (noun)	malt whisky (noun)
whiskey distilled in Scotland; especially whiskey made from malted barley in a pot still	whiskey distilled in Scotland; especially whiskey made from malted barley in a pot still