Reconstruction:Proto-Turkic/ayran

Attested in every branch of Turkic but in Arghu and in Siberian languages (except Khakas, see below). No majority consensus on the origin, but probably from *adïr- +‎ *-gan.

• Róna-Tas and Berta suggest a derivation from Proto-Turkic *ayïr- (“to separate”) for the Oghur branch and its descendants, refusing any possible relation with the following:
  1. An intermediary *yaδaq/ŋ ("churned butter, butter leftover") by Ligeti (1960, 1986), a denominal reflex derived from Proto-Turkic *yād- (“to churn butter”) (whence Khalaj یاماق (yâmaq, “to churn butter”)). The same root would also be compared to the native name of the Ural river, (which in Proto-Turkic is *yāyïk (cf. Ancient Greek Δάϊξ (Dáïx), Δαΐχ (Daḯkh), Γεήχ (Geḗkh) and archaic Russian Яик (Jaik))) by Clauson (1972), also rejected by the authors.
  2. Proto-Turkic *aguŕ (“colostrum, beestings”) (whence the hypothetical Middle Chuvash form *ïră ("an aciduous liquid remaining after butter has been separated from milk or cream")), proposed by Räsänen (1969) and Doerfer (1963, 1975).
  3. Proto-Turkic *ïrga- (“to rock, to pump, to move something from one side to another, to swing”), which is deemed as semantically unsatisfactory.
  4. Old Chinese 酪 (*ɡ·raːɡ) (and Middle Chinese 酪 (lak)) by Pulleybank (1962), who reconstructs this root as *agïrag and posited that this word is a Xiong-Nu word re-analyzed by Turkic and Mongolic speakers as *ayï- instead of *agï-.
  • Agyágasi (2019) demonstrates that historical Chuvash forms and loanwords at large support Róna-Tas's and Berta's etymology.
• Räsänen (1969), on a different entry than the one above, tentatively adopts the root term as Proto-Turkic *adïr- for all Turkic languages except Yakut аарах (aaraq) (which is borrowed from Mongolic *ayïrag). He also thinks that a relation between *ayran and Mongolic *ayïrag exists, but no direction of borrowing or a cognate relation is given by him.
• Yegorov (1964) follows the same argument, saying that Chuvash уйран (ujran, “buttermilk”) is related to Chuvash уйӑр (ujăr, “to separate, to split”).

• Clauson (1972) rejects any relation with Proto-Turkic *adïr- (“to separate”) on the basis of Karakhanid form, and posits that "...but it is very odd that such a sound change should have occurred in [Karakhanid language] and it is prob[ably] merely a false etymology."
• Nişanyan suggests that the drink in question is an Oghuz "Kulturwort", and therefore it spread to other languages via Oghuz Turks. This would explain the problematic -y- sound before -r- in Karakhanid and Khakas reflexes, where the expected reflexes from a genuine Proto-Turkic root would be *aδran and *aźran respectively.

• Altaicists, on the other hand, compare this word with Proto-Mongolic *ayïrag (“koumiss”) (thus Mongolian айраг (ajrag)), Ulch аяра- (“to take fat off butter while it is melting”) and Nanai аярахо (ajaraho, “spoon for taking fat off”), deriving the word from the "Proto-Altaic" noun **ăyVrV ("sour milk, fat melt") (EDAL's V stands for an undetermined vowel sound).

It should be noted that this word was first attested in Dīwān Lughāt al-Turk (11th century), not found in any pre-Islamic texts, save for a particular letter in Old Uyghur written in the 10th century.

*ayran

1. buttermilk, airan (doogh, tan)

• Proto-Oghur: *ayraɣ
  • →? Proto-Mongolic: *ayïrag
    • Mongolian: айраг (ajrag, “koumiss”)
  • Proto-Bulgar: *ï̄raɣ^[1]
    • → Old Hungarian: yiro (i:ro:)
      • → Hungarian: író
    • Old Chuvash: *yăra(n)^[2]
      • → Eastern Mari: йыра (jyra)
      • Chuvash: уйран (ujran)^[3]
        • → Russian: урень (urenʹ)

• Proto-Common Turkic: *ayran

• Agyágasi, Klára (2019) Chuvash Historical Phonetics (Turcologica; 117), Wiesbaden: Harrssowitz, pages 86, 130
• Clauson, Gerard (1972) “ayra:n”, in An Etymological Dictionary of pre-thirteenth-century Turkish, Oxford: Clarendon Press, →ISBN, →OCLC, page 276
• Jegorov, V. G. (1964) “Proto-Turkic/ayran”, in Etimologičeskij slovarʹ čuvašskovo jazyka [Etymological Dictionary of the Chuvash Language] (in Russian), Cheboksary: Čuvašskoje knižnoje izdatelʹstvo, page 270
• Nişanyan, Sevan (2002–) “Proto-Turkic/ayran”, in Nişanyan Sözlük
• Räsänen, Martti (1969) Versuch eines etymologischen Wörterbuchs der Türksprachen (in German), Helsinki: Suomalais-ugrilainen seura, page 12
• Róna-Tas, András, Berta, Árpád, Károly, László (2011) West Old Turkic: Turkic Loanwords in Hungarian (Turcologica; 84), Wiesbaden: Harrassowitz Verlag, pages 464-470
• Starostin, Sergei, Dybo, Anna, Mudrak, Oleg (2003) Etymological dictionary of the Altaic languages (Handbuch der Orientalistik; VIII.8)‎^[1], Leiden, New York, Köln: E.J. Brill
• Ünal, Orçun (2019). Klasik ve Orta Moğolca Söz Varlığında Türkçe Kökenli Kelimeler I (A–D). Journal of Old Turkic Studies, 3(2), 502-615.