Intelligence is a word we invent to describe things we see in nature. We don't "discover" intelligence like it's some natural resource. To say we know nothing about it is also a bit strange. Cognitive science has been studying it for decades. Of course it's hard to give a precise definition, but it's related to capabilities like abstraction, reasoning, planning, problem solving, etc.

Why would a set of dictionary definitions not suffice?

What we know is intelligence is definitely comprised of the trait of adaptability.

E.g. humans get exposed to new LLM model - yeah its powerful - 1 week later - eh, that thing? Yeah it's whatever. I'm still employed.

The human's ability to adapt so efficiently is mind-boggling - so much so it pi1sses sam altman and dario off.