Anything that emulates something else is an emulator. That something else could be hardware, or runtime behavior, or services, or a combination thereof. (It could even be a turtle, although we're talking about computers in this case.)

Wine is an interesting example despite that silly backronym that was abandoned years ago, or perhaps because of it. It not only translates system and API calls, but also provides Windows work-alike services and copies Windows runtime behavior, including undocumented behavior. If it were just an API wrapper or "translation layer", a lot of its functionality wouldn't work.

The shape of a business envelope might not be an equilateral rectangle, but it is still a rectangle.

But go ahead and believe what you want. I'm not looking for an argument.