I’ve been thinking about the word “reality.” It derives from the Latin word res, which simply means “thing.” (The word republic, for instance, comes from res + publica—the thing of the people). Etymologically speaking, reality means something like “thinginess.” A real thing is a thingish thing (which suggests that the phrase “real thing” is redundant).
What, then, is a thing? I don’t quite know what to say to that, except that I know a thing when I see one, and so do you. You can look up thing in the dictionary, but I don’t think you’ll find it very helpful.
In the absence of a good definition of a thing, allow me to highlight one important facet of thinginess: A thing must exist outside the human mind (and outside of language) in order to qualify as a thing. Consider this utterance: “Pumpkin-spice bacon frappuccino donut—is that even a thing?” The speaker is asking, “Does this concoction exist in the physical world where you and I live, or is it just a string of words, or a figment of your imagination?”