It is especially confusing for C and C++ coders, because Rust enums are a completely different thing than C enums, which makes the naming choice worse than just inventing a new name.

Better names would be "tagged union" (which is spot-on descriptive - because it *is* a union with a tag slapped on - but "tagged_union" of course is a bit unwieldy as keyword) or "variant" (which is the name for that thing in C++ and elsewhere since forever - it's not like Rust invented those tagged-union-thingies, it just added some convenient syntax sugar to the language to deal with them).