“Things” have definitions – that is the words that are attached to them and the definition of those words as found in a dictionary – and “meanings”. What I mean by Meaning here is what goes on in my mind when I think about that particular thing. So, if you ask me what a tree is, I would try and define it or refer you to the definition in a dictionary. If you ask what tree means to me what comes into my mind is a collection of images, definitions and connections which, if I tried to describe, would come out as a disjointed stream of consciousness which would be only a feeble precis of what is actually in my mind. If I am going to talk about something, it is the definitions that matter. If I am going to think about something, it is the Meaning that matters. Another person will have a different but related Meaning in their minds. We might use the definition to check that we were talking about the same thing.
If I am to have a discussion with another person, we need to definitions in common in order to have a fruitful discussion. If one of us was not familiar with the topic, they would need to be educated before they could have any sort of useful discussion. If the discussion was related to trees, this education might have to include definitions of leaves, branches, wood, bark, and forests.
However, if I am going to think about something, it is the Meaning that is important. This is far richer than the a list of definitions.,For me this would include memories of particular trees, that I have climbed, fallen out of, picked fruit from, cut down and made things out of wood from. Definitions are just a sometimes optional part of this.
In particular, if I think creatively, it is Meanings that I use.
The Meanings of different things are all linked together. They cannot be untangled because those links are part of the meaning and undoing links reduce the extent and richness of the Meanings.
Meanings are unique to the individual and can only be explored by that individual. They are therefore, by definition, outside science as strictly defined.