I consider the term "compiler" to be very generic, and to cover a wide spectrum of tools ranging from those which compile from one high-level programming langua

I consider the term "compiler" to be very generic, and to cover a wide spectrum of tools ranging from those which compile from one high-level programming language to a slightly lower-level language (e.g. TypeScript), right down those which produce machine code (e.g. GCC/Clang+LLVM). In fact several major compilers (such as GHC and the first C++ compiler, cfront) started out by using C as their backend. "Transpiler", which is arguably somewhat of a buzzword, typically refers to compilers where the source and target language are either the same, or at a very similar level of abstraction; I agree with n4r9 in considering them a particular type of compiler. Even so, the implementation described in the article compiles from a high-level language, JavaScript, to a considerably lower-level language, C++; so even if we exclude transpilers from our definition of what constitutes a true compiler I still think it's a valid term to apply in this case.