fry vs french-fry

fry is a noun but french-fry is not a noun.

Word	Noun	Adjective	Verb	Adverb
fry	Yes	No	Yes	No
french-fry	No	No	Yes	No

As verbs, french-fry is a hyponym of fry; that is, french-fry is a word with a more specific, narrower meaning than fry:

Other hyponyms of fry include frizzle, griddle, pan-fry, deep-fat-fry, deep-fry, stir fry, saute.

fry (noun)	french-fry (noun)
a young person of either sex

fry (verb)	french-fry (verb)
cook in hot fat or oil	cook by immersing in fat
kill by electrocution, as in the electric chair
be excessively hot