There's elevator-flap mixing, and there's using your ailerons as flaps (flaperons). Those are seperate and distinct mixes, done for seperate and distinct reasons. If you don't feel comfortable specifying what you're doing, don't expect people to automatically understand what you mean. What's wrong with calling what it is, rather than trying to misuse another term? If a fellow is asking about mixing his elevator to his flaps and you start talking about flaperons you'll look like an idiot (and rightly so!).