white potato vs Irish potato

white potato and Irish potato both are nouns.

Word	Noun	Adjective	Verb	Adverb
white potato	Yes	No	No	No
Irish potato	Yes	No	No	No

As nouns, white potato and Irish potato are synonyms defined as:

white potato and Irish potato: an edible tuber native to South America; a staple food of Ireland

Other synonyms of white potato include murphy, potato, spud, tater.

white potato (noun)	Irish potato (noun)
an edible tuber native to South America; a staple food of Ireland	an edible tuber native to South America; a staple food of Ireland
annual native to South America having underground stolons bearing edible starchy tubers; widely cultivated as a garden vegetable; vines are poisonous