No, the right word is translator. A compiler generally creates a form optimised for execution, like machine code or bytecodes. A translator creates source code files from other source code files.

The program the poster was referring to is actually a disassembler, taking Microsoft IL (assembly for the virtual machine) and converting it to a .Net language. So you might;

- compile C# to Microsoft IL - decompile the IL back to IronPython - use that as the basis of a CPython version.