Earlier quoted context omitted.
I've not read Aristotle directly but translating eudaimonia was an example in the book that I mentioned. The argument was that eudaimonia is often translated as happiness but that doesn't make sense in contexts where we talk about a soldier dying experiencing eudaimonia (suggesting a loose translation).
You don't think it possible for some one to die happy?
This question itself seems to be a perfect example of the point that the word is worse than meaningless. Worse because people use it like it has a useful meaning.
One can die in a state that has a lot of the qualities or features that overlap with other states that people call happy, but that doesn't make them equal or equivalent.