“So then because thou are lukewarm, and neither cold nor hot, I will spue thee out of my mouth.”
That’s from the Bible, King James Version. But not from the Gospel According to Luke! It’s from the Revelation, chapter 3, verse 16. It sets the tone for lukewarm: unpleasantly tepid. Not a nice cold drink, not a nice hot one. Just for spitting out. I can confirm that it lives up to expectorations – I have sensitive teeth, so the only kind of water I can rinse with after brushing is lukewarm. I spit it out not because it’s unpleasant, but because it’s the only comfortable temperature. While lukewarm isn’t so great for drinking, it’s not bad for some other things. We may find extremes attractive, but you can’t live all of your life that way.
Look: There’s a Dutch word that may be related. The word is leuk (the Dutch eu is said like French eu, not like German eu). There’s a store in Collingwood, Ontario, with that name – although they have affected an inappropriate dieresis, Lëuk – and it sells very comfortable and appealing home furnishings and clothes, at slightly less comfortable prices. Why would you name a store “lukwarm”? Well, in Dutch, leuk means ‘nice, pleasant, enjoyable’ or ‘amusing’ or ‘pretty’ or just generally ‘likeable’. After all, not too hot and not too cold is just right, right? What is lately called the “Goldilocks solution”?
But Dutch for ‘lukewarm’ is not leuk. It’s lauw. Which is definitely related to lukewarm. The etymology of lukewarm, it turns out, has some cross-currents. Let’s start with the obvious fact that it’s luke + warm. What is this luke? It’s an old word, now disused except in this compound; it means (meant) ‘tepid’… which is to say ‘lukewarm’. The historical citations suggest that saying luke-warm or luke warm was saying “warm, but not warm warm, just luke warm.” Middling. But anyway, where does luke come from?
Where it does not come from is the name Luke, which we get from the Bible (New Testament). No, this lower-case luke comes from Old English hléow, which also became the modern word lew, which is also unrelated to the name Lew (short for Lewis), and also means ‘lukewarm’ but also means ‘sheltered from the wind’, which is to say, in the lee, which is unrelated to the name Lee but is related to hléow and thus to lew and luke. (The name Lee comes from the same root as lea as in Avonlea. If that helps.)
So wait: how did hléow become luke? Where did that k come from? Well, it may have come from cross-influence from wlæc, which means ‘lukewarm; tepid’. Now, it seems that wlæc does not come from the same root as hléow. But somehow the two words mixed and produced something of an average. Sort of like your hot and cold taps running together.
Anyway, that hléow is also evidently related to Dutch lauw. Now, the Oxford English Dictionary says “Notwithstanding the resemblance in form and meaning, it seems impossible to connect the word [luke] etymologically with modern Dutch leuk.” But if you go to Wiktionary, it cites Etymologisch Woordenboek van het Nederlands to assert say that leuk is “probably” related to lauw, which traces to Proto-Germanic hléwaz, which is the ancestor of hléow. So the trail of evidence is not hot hot, but it’s not cold either. Well, I can be comfortable with it. The OED may update its etymological note in the fullness of time.
But how about that name Luke? That’s after the author of the Gospel According to Luke. He was not one of the original twelve apostles but was an early prominent figure, very enthusiastic (not just lukewarm) about this Jesus guy. He was Greek, a teacher and physician, born in Antioch; his name in Greek is Λουκᾶς, Loukas, which is the same as Latin Lucas (from which Italian Luca, French Luc, German Lukas, and so on). A common derivation of the name is as meaning ‘person from Lucania’, which was a region of southern Italy – once occupied by Greeks – just north of the Calabrian peninsula, and thus of a climate somewhat more warm than luke. But Lucas is at least as likely to come from Latin Lucius, meaning ‘bright’ or ‘born at dawn’ (related to lux ‘light’). So. Fiat lux?Fiat Lukes. And fiat leuk.