What would you call a filet of Ribeye?

I don't call it anything. A filet is a boneless cut of meat (any meat, including fish). A Ribeye is a specific part of the cow. Therefore, a filet of Ribeye is just that--a piece of Ribeye that doesn't have bone in it. You can call it a filet if you want to, just know that most people will assume that you are speaking about filet mignon, which is an entirely different part of the cow.

A filet means a slab of meat that's cut with the meat grain, while a steak is cut against the grain. And, I don't know why anyone would filet a rib eye. But, if they did, I would call it a fileted rib eye.

There is no such thing unless your butcher has dreamed up a new name for his Ribeye

The rib eye or "ribeye" was originally, as the name implies, the center best portion of the rib steak, without the bone.

Over here we call it a Scotch Steak

H'man

It is known as Scotch fillet in Australia and New Zealand. According to Wikipedia, it is also called Delmonico steak or Spencer steak. My suggest is “6-to-12 Steak” as the beef it is made from spans from ribs six through twelve.

I'd call it beef. (There are fish fillet also).