french fries vs french-fried potatoes

french fries and french-fried potatoes both are nouns.

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

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

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

Other synonyms of french fries include chips, fries.

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