I particularly like George Ledyard's contribution to this thread
. I think he provides a clear, non-obfuscated definition of aiki that can be understood in practical terms, without rainbows and unicorns, but also without being exclusively bound to fascia or myofascial whatsis. He also provides a sensible comparison with how O-Sensei used the term, which I think is particularly useful not as some kind of aikido-fundamentalist proscriptive definition, but because I can see where the two views are talking about the same thing, just with a different focus or POV (sort of like looking at the same tree from slightly different angles).
Well, I, for one, have never proposed a definition "exclusively bound to fascia or myofascial whatsis". But I do think that O-Sensei's technical methods are entwined with his philosophy - so much so that you can't get one without the other without it becoming something quite different.
For example, the term "Take Musu Aiki" that's cited in the linked post. The definition given isn't wrong - but it's not complete either, and that will change the implications.