French fries are known as such because thin strips of vegetable are known as
julienne in
French. Julienne
potatoes doesn't exactly roll off of most
American tongues, and thus such potatoes were referred to as
French-cut. French-cut further devolved into just French, giving us
French fried potatoes. Since potatoes were accounting for most all of the
French fried products, potatoes was dropped, and
fried was morphed into
fry.
Giving us the french fry.
This is the etymology as I understand it. Please let me know if you have corrections.