Compiling is independent of source and target language, although it is mostly used to describe transformation from a higher-level human friendly language into a lower-level machine friendly language. Even so, the defined meaning of compiling is independent of the source and target languages. If you want to use the word "transpiling", you would have to define it in terms of compiling; transpiling is a special case of compiling, where the source and target languages have such and such properties.