Concepts like the parent's "fat" example are cultural relatives. Someone can be called "fat" despite actively being proportionally skinnier or having a lower BMI.
But even that has at least a basis in the physical world. A skeleton can't be colloquially fat.
The root problem is that "consciousness" does not even have that. It's metaphysical and has no ability to be measured or observed or confirmed by an outside observer. Because even if it did not exist, the object claiming it would still be claiming it. And objects that do not claim it may in fact have it.
While the top comment may have used poor examples, it feels remarkably uncharitable to actually suggest "what is consciousness" is an equivalent discussion to "how long should a meter be?"
If you define consciousness as "being human", you would just have someone asking a new question - what is "fooblefobble?" Where "fooblefobble" is what we mean when we talk about consciousness today. The question doesn't get answered by being arbitrary in this context, you just necessitate a new word.