french-fried potatoes vs french fries

french-fried potatoes and french fries both are nouns.

Word	Noun	Adjective	Verb	Adverb
french-fried potatoes	Yes	No	No	No
french fries	Yes	No	No	No

As nouns, french-fried potatoes and french fries are synonyms defined as:

french-fried potatoes and french fries: strips of potato fried in deep fat

Other synonyms of french-fried potatoes include chips, fries.

french-fried potatoes (noun)	french fries (noun)
strips of potato fried in deep fat	strips of potato fried in deep fat