Lukewarm isn't a good candidate for an antonym, because it describes a specific temperature. Not an exact specific temperature, one can't mark "lukewarm" on a thermometer, but consider being presented with two bowls of soup and asked which is "more lukewarm". Either neither is, one is and the other isn't, or both are, lukewarm. In the last case, how do you decide which is more so? Is it the slightly warmer one, or the slightly cooler one?
It's like with cooking steak: you could say well-done is the antonym of rare, I'd agree[†] with that as a premise. But medium doesn't have an antonym, and it makes less sense to describe the antonym of medium-rare as medium-well, they aren't opposites.
[†] If you would prefer "blue" or even "raw" for maximum contrast, that's fine by me, both cool and cold are antonyms[‡] of warm, same principle.
> Lukewarm isn't a good candidate for an antonym, because it describes a specific temperature. Not an exact specific temperature, one can't mark "lukewarm" on a thermometer, but consider being presented with two bowls of soup and asked which is "more lukewarm". Either neither is, one is and the other isn't, or both are, lukewarm. In the last case, how do you decide which is more so? Is it the slightly warmer one, or the slightly cooler one?
Wait, but if one is hot, and one is medium, I'm obviously picking the medium one. Seems easy enough to do a comparison to me.
I think perhaps a stronger reframing of your argument is that if you want an antonym, you want to take what you have and flip around some middle point, e.g. happy gets flipped to sad because it's "flipped" around neutral, etc. But lukewarm pretty much is the middle point, so flipping it has no effect.
> Wait, but if one is hot, and one is medium, I'm obviously picking the medium one. Seems easy enough to do a comparison to me.
Ok, I can see how what I said was unclear. Maybe not unclear, but it could have been phrased more plainly. If one is lukewarm and the other is not, the comparison is easy. But if both are plausibly lukewarm and one is a little warmer than the other, which one is "more" lukewarm? That isn't really how the word works, y'know? I don't think you'd get a repeatable answer out of different people on that, whereas a bowl of lukewarm soup, and one which is not-lukewarm in either direction, there will be a strong consensus as to which is which.
Re: repeatability, if you presented a bunch of people with bowls of soup and asked them to label them as hot, warm, or lukewarm, you would not get perfect consensus. However, there would be some consensus.
The problem is that the word "warm" can mean a point on a temperature scale as well as a comparable quality. You can use it as a comparative adjective: this soup is warmer than the other soup. You can also use it as a label: this soup is warm. Lukewarm only works as a label and you would not say that the soup is more lukewarm than the other.
"Hot" is similar to "warm" in that regard, as it can be used to compare and to label.
There are other temperature-related words which are like lukewarm, and can be used to label but not to compare. Scalding is one that comes to mind, and it has antonyms such as frigid.
That depends where "medium" falls on the temperature scale. If we say that lukewarm is the medial point, then what you wrote makes sense. However, if we say that lukewarm is warmer than whatever the medial point is, then it makes sense to have a lukecold-like antonym.
I never thought about this and this is a delightful thought exercise. Sometimes I use lukewarm to mean medium, usually when describing the weather. Kind of like where it's neither cool nor warm. However, sometimes I use it to describe something that is warmer than the ambient medium point, usually when describing bathwater and tea temperature.
Re: antonyms, I see cold as an antonym of hot. Cool as an antonym of warm. Is lukewarm the midpoint between cool and warm? Sometimes, maybe, but probably it's a bit on the warmer side of neutral.
Plenty of adjectives describe fuzzy-but-narrowly-defined states and yet can both be compared (in the sense of "more X") and have serviceable antonyms. Examples: blue, happy, inflated, trivial.
You actually appear to be touching upon something different, which is that a word describing a state which is in the middle, between two extremes, could actually have two polar-opposite antonyms depending on context.
Context is key here and note that all the examples in the article provide that context, e.g. "the AC needs repairing as it's only lukecool". It is difficult talk about antonyms without context for this reason.
It's like with cooking steak: you could say well-done is the antonym of rare, I'd agree[†] with that as a premise. But medium doesn't have an antonym, and it makes less sense to describe the antonym of medium-rare as medium-well, they aren't opposites.
[†] If you would prefer "blue" or even "raw" for maximum contrast, that's fine by me, both cool and cold are antonyms[‡] of warm, same principle.
[‡]: https://www.merriam-webster.com/thesaurus/warm