People are still coming up with definitions of consciousness and then those definitions end up being attacked by others who disagree with the foundation of the definition, which is - if you will recall - also what happened with the meter, over the course of centuries, until it was very recently redefined to be "unambiguous", but arbitrary. This was possible because few people had any particular emotional investment in the definition of a meter, and it is probable that consciousness will be eventually defined to mean that only humans can be conscious, which may be dissatisfying but would be true throughout the universe, like a meter. If the question then becomes "what defines a human" and "why a human", then I ask, why 1/299792458 of a second?
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.