I may be misunderstanding you, but I think "Nabataean" here is just the dialect of (Western) Aramaic used by the Nabataeans and found written in the Nabataean script, comprising a corpus of some 6.000 inscriptions.

Perhaps more likely cognate to Avestan 𐬐𐬀𐬛𐬁 /kadā/, Sanskrit कदा /kadā́/? Both are held to derive from Proto-Indo-Iranian *kadáH. So a chance similarity to Aramaic.

Have a look at Peter Huber's "On the Old Babylonian Understanding of Sumerian Grammar" available at cdli.earth/articles/cdl...

It has some currency in Denmark too, especially in "progressive" families from the sixties and onwards, it became common for parents to teach their children to address them by their first name. Primarily an urban phenomenon. It seems to be fading these days.

Good point, but presumably there was no quantitative difference between short and ḥaṭef vowels in Tiberian pronunciation (according to Khan's "The Tiberian Pronunciation Tradition of Biblical Hebrew").

Is it a loan from Indo-Aryan? But how does the the -k- come to be?

Would the ⲟⲩ- be the Coptic indefinite article, then? Or just an epenthetic vowel inserted to prevent a word from starting with two consonants?

This was found on the coast of Fanø, an island on the south-western coast of Jutland, i.e. facing the North Sea approximately in the same direction that Doggerland would have been.

It is roughly 6 cm long.

There's a bit a with a bottom loop connected to long oblique lines a tad to the left of the sīn that kinda looks like a Syriac (ʾEsṭrangēlā) ṭēt (ܛ), and Syriac was used for some time in Central Asia, but then again the rest of the letterforms don't seem to match up to Syriac as far as I can see.

I can kind of see what you mean. This is from the right-hand cartouche and contains what might be a ـسـ (sīn, marked 1) and what could perhaps be a ـة (tāʔ marbūṭa, marked 2), but I can't seem to make sense of the rest.

After staring at it intensely for some time, I also arrived at a best bet that it was some kind of Arabic script calligraphy, but I couldn't make out any words. To the best of my knowledge, this is the lid of the box photographed from above (i.e. not upside down). The box hasn't been opened.

Some context: The box belonged to a Danish military officer and explorer who went on several expeditions to Central Asia in the 1890s, particularly the Emirate of Bukhara. It was left to his family; they think he acquired it during those expeditions, but nothing certain is known of its provenance.