INTXAUR

The Basque "nut" - "intxaur" - technically is a Kartvelian adjective "inchauri", which has "intxa" as the root. The chain is complicated, but it is impossible to ignore it.

First, we find ინჩახუ (inchakhu) - bird's crop. Also ინჩი-ბინჩი (inchi-binchi) - "the slightest". First of all, it overlaps with the size of a bird's throat, which, in turn, roughly and unexpectedly coincides with English inch.

Let's go further. In Chanturia's dictionary there is a word ინჩხლი (inchkhli) - "borage". It doesn't look like a nut. With a high degree of probability, we can assume that the word ინჩხილი (inchkhili) in Otara Kajaia's dictionary (literally, "inch fruit") is also "borage", because Kajaia calls it simply მცენარეა ერთგვარი - "a kind of plant".

We get back to ინჩხლი (inchkhli) and learn that it has a variety - ანჩხლა (anchkhla), the same borage. This already hints that the root can be "anch". In search for it we come across ანჩარი (anchari) – the anchar, sung by Pushkin, whose fruits really look like walnuts, and also ანჩახი (anchakhi) - saddle tree (wooden part of the saddle). You can already draw conclusions.

The problem is that in the Basque dictionary this word has a lot of possible spellings, and they all can be interpreted from the Kartvelian point of view: unsaur, intxaur, intzaur, inzaur, entzagur, entzuur, etsagur, etzagur, etzabur, etxa(g)ur, extabur, exabur, etzaur, intxoor, intxor, intxur, intsaur, intzagur, intzagor, intzoor, intxaur, itzagur, itzaur, itzigur.