[To be clear, the below is me agreeing with you]

Norwegian is almost as compound-happy as German, and we could've filled many volumes with compounds. But what generally happens for one of the compunds to enter the dictionary is that the compound needs to have a meaning that is non-obvious from the individual parts, at least to some people, and typically that the compound has a non-obvious meaning if interpreted as two separate words.

E.g. "akterutseilt" is an example. "Akterut" means behind, aft. "Seilt" means sailed. "Behind sailed" helps as a way to remember it, but it's not obvious whether it's strictly a sailing term, or means that you've been left behind or have left someone else behind.

In this case if you say someone has been akterutseilt, it means they've been metaphorically left behind, often by their own failure to keep up.

Those kinds of compounds deserve dictionary entries whether they are actually written in two words or one, because they function as a single unit however it is written.

I think black hole is a perfect example in English. And in fact, this is a compound that is written in two words in Norwegian as well, but is in Norwegian dictionaries despite that[1] as "svart hull".

[1] https://ordbokene.no/bm/svart%20hull

> Adding two words together creates a new and different concept. The permutations necessary to represent every concept ever formed by combining two or more different words would be endless.

May I introduce you to the German language?

We have "gesundheitszeugnis" (health certificate) and "bärenstark" (strong as a bear), and of course "[der] Donaudampfschifffahrtsgesellschaftskapitän" ([the] Danube Steamship Navigation Company Captain) and "[Das] Rindfleischetikettierungsüberwachungsaufgabenübertragungsgesetz" ([the] cattle marking and beef labeling supervision duties delegation law).

Boiling point?

Yeah, but the nice thing about natural language is, it doesn't matter what you think. People talk because they want to communicate something. You can try to talk your pet language at other people, but you will fail at communicating. So things have a happy way of sorting themselves out.

Well, being pedantic, my favorite hobby:

Frozen water represents a state change and that different state commonly gets its own word: ice/water/steam equates to solid/liquid/gas

Boiling/freezing water represents the state of the liquid, not the transition. Its descriptive. Water boils away into steam, or freezes into ice.

Should we consider luke-warm water also singular? What about body-temperature water? cool water? It makes sense not to treat adjectives/descriptive words combined with the subject as singular because the definition already exists in the root of the words (meaning of adjective word + meaning of subject word). Blue clay is another example, why would that be a singular?

It really only makes sense to me in the rare cases where the combination words represent something different or non obvious than the combined meanings of the two words (i.e to 'give up')

But water that has boiled into gas also gets a word: steam.

As far as I'm aware, there is no separate word for freezing water -- i.e. water that is very cold and will, if it continues to get colder (and has something to crystallise around), turn into ice.

So the symmetry seems complete: ice -> freezing water -> water -> boiling water -> steam.

Steam?

As an idiomatic expression, "Hot water" = "trouble".

Are there idiomatic expressions for warm/cold/dirty water, which mean something other than a literal adjective describing the temperature or condition of water?

> dirty water

Depending on the context you got sewage, slush, runoff, murk, waste etc.

And even more confounding, what's "water ice?"

https://www.ritasice.com

Yeah, this article brings up a good point per se, but then defeats itself with nonsensical analysis and examples

It used to be iced cream, which is more descriptive.

Ice cream is a shortened pronunciation.

Really? none are one word? How about "of course"?