Ah, a little lesson about languages from up north: We compound words.
For example, in order to say "processing power", the only correct way to say it would be "processeringskraft" (processering = processing, kraft = power). That does not make "processeringskraft" a word on its own, as it is simply a compound required by our grammar.
Likewise, "flyskam" is a compound, and simply how we'd say "flight shame". While it might be a newly invented term growing in popularity, it is not a newly invented word.
It really depends on what you consider a word. I haven't heard your distinction between a word and a term widely made. You could (and many linguists do) instead say that compounds in English can contain a space, that is, some English words have spaces (or hyphens). The reason for considering a compound as a separate word is that it can have meaning that is more than the sum of its parts. The linguistic jargon for a compound where the meaning can't be easily determined from it's parts is non-transparent.
What I am implying is that "Flight shame" and "flyskam" are entirely identical entities. That is, to consider "flyskam" in our various nordic languages a word, one must also consider "flight shame" in the English language a word.
As a local, I would not perceive "flyskam" as a word outside of trickery attempts to construct hilariously long words, where our languages should really be disqualified due to unfair grammar.
I would argue that even 'flight shame' is a new term that has a specific, recently acquired meaning in environmental context, different from what it would have a couple years ago. A great example of how language is dynamic and how reality and context shapes new meanings from existing words.
So is it a bit like "weekend" or "website" in the sense that those were originally two separate words that were combined enough to create a convention that they should be one "new" word?
That is an entirely different concept from compound words such as "flyskam", which is simply how "fly" and "skam" are to be written to convey this meaning. "Jeg har flyskam" means "I have flight/airplane shame" (i.e. shame due to flying), but "Jeg har fly skam" would mean "I have shame that is flight", which is nonsense.
A better example of the meaning imposed by compounding would be "En dansklærer", which in verbose translation means "A teacher of the Danish language", as opposed to "En dansk lærer", meaning "A teacher who is Danish". We can also combine them, with "En dansk dansklærer" meaning "A teacher of the Danish language who is Danish".
"Weekend", on the other hand, is a word on its own after having morphed over time into its own entity, and even adopted unchanged into Nordic languages (apart from local pronunciation, of course). That several words morph into a single, new and unique word is not uncommon, although usually with greater change than just a lost white space.
I believe this is true since otherwise you would find a lot pf compound words in the dictionary. On the other hand there are of course some compound words in the SAOL.
Here is a word you probably wont find in a Swedish dictionary: flagstångsknopsputspoleringsmedelsflaskkorksetikettpåklistrare.
Yes, in Swedish. I'm Danish, though, so felt more comfortable making a Danish example.
I also felt that many might not understand just how incredibly close our languages are, and that adding the language I used to the comment would likely distract from the point as a result.
"Processorkraft" means "processor power", and "beräkningskraft" ("beregningskraft" in Danish) translates to "computing power".
The correct Swedish translation for "processing power" is "bearbetningskraft"/"behandlingskraft". This sounds a bit awkward to my Danish ear, however. In Danish, apart from "bearbejdningskraft"/"behandlingskraft", we also have "processeringskraft", which is a normal term. This may also work non-awkwardly in Swedish, but hard to sway without a Swedish ear.
They are of cause all commonly used interchangeably, but they have subtle differences in their literal meanings.
For example, in order to say "processing power", the only correct way to say it would be "processeringskraft" (processering = processing, kraft = power). That does not make "processeringskraft" a word on its own, as it is simply a compound required by our grammar.
Likewise, "flyskam" is a compound, and simply how we'd say "flight shame". While it might be a newly invented term growing in popularity, it is not a newly invented word.