I agree with you on the need for definitions.

We spent decades slowly working towards this most recent sprint towards AI without ever landing on definitions of intelligence, consciousness, or sentience. More importantly, we never agreed on a way to recognize those concepts.

I also see those definitions as impossible to nail down though. At best we can approach it like disease - list a number of measurable traits or symptoms we notice, draw a circle around them, and give that circle a name. Then we can presume to know what may cause that specific list of traits or symptoms, but we really won't ever know as the systems are too complex and can never be isolated in a way that we can test parts without having to test the whole.

At the end of the day all we'll ever be able to say is "well it’s doing a thing that looks like thinking, ergo it’s thinking”. That isn't lazy, its acknowledging the limitations of trying to define or measure something that really is a fundamental unknown to us.