The meaning of words comes from usage. Originally "intelligence" was used to refer to a capability of humans and certain animals, but nowadays "AI" has become p

The meaning of words comes from usage. Originally "intelligence" was used to refer to a capability of humans and certain animals, but nowadays "AI" has become part of the common lexicon, and isn't going anywhere, so any dictionary definition needs to include that usage too (even if not everyone agrees that machines can be "intelligent"). Of course it's interesting to go beyond word usage and "I know it when I see it", and try to define what intelligence actually is - what, objectively, is this capability that people see and call intelligence? I think many people would struggle if asked this, but "ability to learn", and "ability to solve problems" are perhaps common themes that one might expect to come up, and is why many people are OK with the idea of AI, but would balk at describing the sun as intelligent. Of course we can do better than these intuitive definitions, by considering the evolutionary origins of intelligence, and what it really is, but that's not relevant to a discussion of what the word means in everyday usage, and what types of thing people are willing to ascribe intelligence to.