Every new word coined is a wonder. There used to be a feeling or a phenomenon or a concept that was vague and kept slipping from your grasp, but now – now there is a word for it! A single word, that means exactly what you want, like a flagpole declaring ownership over a vast wilderness.
One of my favorite examples from recent memory: in Anathem, Neal Stephenson uses the word “upsight”. He doesn’t define it. That’s just the way words from a speculative universe are. But it’s meaning is instantly clear from the context. It’s a riff on the well-known “insight”, of course, but subtly different, and much more powerful. To have insight into something means to have a deep and accurate understanding of it, often in ways opaque to most. What could “upsight” mean? I propose: to have an upsight, one must not just deeply and accurately understand something, but generalize that understanding to a much broader class of things. To understand addition of integers well would give you insight into it, but to understand that it is but a trivial example of a group would give you an upsight.