Many thanks desi4life for taking time on this, I am however sure I am missing a trick here, is the answer staring me in the face but I can't see it?
Etymology 1: I know خیر/xeyr means "good" in Arabic & I am desperately hoping that this is not the same خیر/xeyr in نه خیر.
Etymology 2 I can see that it says خیر is a 'Clipping of نه خیر', but where does it say what خیر itself means? It is obvious the key part of نه خیر in نه/nah "no" so what does خیر mean here, what does it add, is it used in other words?
Also isn't "Clipping of نه خیر" a different way of saying "we don't know"?