Èrsh language
The Èrsh language was the language of the Èr or Èrs people, hypothetical Nakh-speaking people argued for by Amjad Jaimoukha in his book The Chechens: A Handbook. Examples of placenames. The capital of the Èrs (which was later turned into a fortress by Urartu) was called Èribuni (later turned into and used as a fortress by the Urartian state). Amjad Jaimoukha argued that "buni" is from a Nakh root, meaning 'shelter' or 'home' (giving rise to the modern Chechen word "bun", 'a cabin, or small house'). According to him, Erebuni meant "the home of the Èrs". It  corresponds to modern Yerevan. However, this theory is not accepted by mainstream linguists and is considered problematic, namely because Chechen "bun" initially derives from the Armenian word "buyn" (բույն) for "nest" or "lair", from Proto-Indo-European *bʰeuH-no-, from *bʰeuH- (“to be; to grow”). Cognates include Sanskrit भुवन (bhúvana, "world"), Albanian "bun" ("shepherd's hut") and Middle Persian بن "bun" ("bottom"). In the "Georgian Chronicles", Leonti Mroveli refers to Lake Sevan as "Lake Ereta". The name of the Arax is also attributed to the Èrs. It is also called the Yeraskhi. The Armenian name is "Yeraskhadzor" (which Jaimoukha identifies  as "Èr" + "khi", a Nakh water body suffix, + Armenian "dzor" gorge). However, according to Urartologist Paul Zimansky, Hurro-Urartian "-khi" is a plural/tribal denotation and not a hydronym, rendering Jaimoukha's theory incorrect.