If you wish to "define" enlightenment, please sit this conversation out because if you don't understand it such that you need to define it, I personally don't think you know it at all. I've seen too many "debates" from people who try to "define" the terms only to find they were completely ignorant of the subject matter. Lest anyone takes offense, I have been one of those people.
What's wrong with seeking to define the terms of a discussion, especially when it's blatantly obvious that people are using differing and contradictory definitions? I personally think you're wrong, that "enlightenment" can't be usefully defined. The thing is, a useful definition doesn't mean complete enumeration. It doesn't mean you're writing down a recipe or a formula. It doesn't mean that you're encompassing the thing itself. I can, for example, usefully define "from zero to infinity" for all kinds of practical purposes (I'll give you a specific case if you want one; it has to do with parallel processing), but that's not to say that I've therefore somehow encompassed the experience of all numbers from one to infinity. Definition isn't the same thing as constraint; please don't take it as such.