I tend to take a more technical definition of it. Iāll link to another thread where we discussed it, but once upon a time, me and another guy figured out a cyborg scale.
It does tend to cut through some of the nebulous philosiphy, but at the same time a mechanistic outlook on the subject kind of misses the point of being a human cyborg. (note, humans are invariably messy to define)
I think the best answer will combine both philosiphy and factual definition. That being said, a complete answer is probably impossible to define.