Compiling is the correct terminology here. Nim transpiles to JavaScript, but it compiles to C and C++. You don't say that Rust transpiles to LLVM IR, do you?
Mad respect for you Dom, but why would going from Nim -> JS be Transpiling and Nim-> C++ be compiling? Both go from a high level Lang to another high level Lang.
I would say compiles is a more general form of transpiles. Transpiling meaning it compiles into a higher level form i.e. c, C++, JavaScript, and compile meaning it compiles into a more lower level form i.e assembly, bytecode, etc?