Well you may ask whether it would be wise to use this word in ordinary discourse. It seems an affront, phonier than phrenology. What are we to make of it? Pick at its form and you may come up with an assortment bits that look like they make nephritis or sphere or rephrase, but nope. Well, yes, there is nope, and spore and hope and posher and quite a few others. But all of that will leave you none the wiser.
You can see that ph at the start, long a mark of a classical (specifically Greek) origin but also seen in recent times on some slang terms. We can assume this is not slang, since it’s not a respelling of an English word and it has Greek morphology, specifically the esis ending, which is common on words such as catachresis and hysteresis that only grad-school dweebs know or care about. (I was one. I know.) So what did it mean in Greek?
The Greek original, ϕρόνησις, meant ‘thought, judgement, wisdom, prudence’, et cetera and all that good stuff. It was taken into Latin to mean ‘wisdom’. In English, it first named a personification of wisdom. Now, when it’s used, it’s generally used to mean ‘practical wisdom, good judgement, sound understanding’.
So you can use this word as a hidden dagger if you want. “I feel that this proposal demonstrates an intriguing lack of phronesis.” You can generally take it on trust that your hearers will make an assumption about a word they don’t know. However, one or two of them might call your bluff – ask you or look in the dictionary. So perhaps don’t use it. I counsel phronesis.