Empyrean (DD definition link)
Ordinarily, I'd be intrigued by any Greek etymology, but empyrean's origins for "of or from fire" devolving into "from the highest heaven" is due to a mistaken association with "imperial" and then an attempt to reassociate the word with "fire," in a pseudo-ex-post-facto definition. Yes, the heavens/sky were the realm of Zeus, the ruler of the Greek gods, but Zeus didn't control the sun (that was Apollo Helios), and the heavens weren't the highest realm of the Greek gods (that was the quintessence). There is some latent association that the heavens contained the "fire" element, but so did Hephaestus' forge, under Mt. Aetna, and we could just as easily be using empyrean to describe in the earth or hell then... So, we are left with an original meaning and usage which got bastardized along the way, and then wrongly reconciled with some lay understanding of ancient Greek culture. Anyone's use of this word is hardly empyrean? No. Planes fly in the empyrean realm? That just sounds pretentious and unnatural. We all aspire to reach empyrean heights in our lives? Again, too pretentious. Plaintiff's counsel had empyrean goals about winning his case despite the lack of credibility of his client? That's the ticket. If the word sounds too silly for ordinary, even among the erudite, usage, then its usage must be accompanied by sarcasm.