Reconstruction:Proto-Slavic/avorъ

Rather unlikely from intermediary *āorъ, having been borrowed from Proto-West Germanic *ahurn (“maple”), particularly from a late form without intervocalic [h].[1] Otherwise, maybe from the same European substrate[1] after the underlying language underwent a sound change from [k] to [v] or a sound shift of comparable consonants. The later borrowing into Proto-Slavic is more probable due to the retention of the exact synonym *klenъ. Compare Latin acer and Ancient Greek ἄκαστος (ákastos).

Adding to that, the maple (Acer) grew only in the western half and particularly the Norway maple (Acer platanoides) as its most widespread kind reached only the western border of the Yamna culture in case that both were even as far distributed from Europe up to there as nowadays.[2][3] On the one hand, the frequency of the Norway maple is condensed into Europe, on the other hand, it is considered native as well to the eastern end of the Caucasus[3] but this does not exclude it having been introduced as it might not have been recorded. If any maple overall only recently extended up to the Caspian-Pontic steppe and surrounding regions, back then it might not have even been adjacent to the Yamna culture at all. This makes a borrowing from a substrate into ancient or early medieval Indo-European languages substantially necessary. Non-cognate Ancient Greek σφένδᾰμνος (sphéndamnos, “maple”) and Old Armenian դղքի (dłkʻi, “maple”) may have a substrate etymology as well even though a possible internal formation was also considered for Ancient Greek.

If Germanic, Latin and Greek words are of native origin, they might derive from Proto-Indo-European *h₂eḱ- (“sharp”) which is supposed to refer to the shape of the leaves.

*àvorъ m[4][5]

1. maple (any plant of the genus Acer)

   Synonym: *klenъ

• East Slavic:
  • Old Ruthenian: ꙗ́воръ (jávor)
    • Belarusian: я́вар (jávar)
    • Carpathian Rusyn: я́вур (jávur)
    • Ukrainian: я́вір (jávir); явор (javor) (dialectal)
  • Russian: я́вор (jávor)
• South Slavic:
  • Old Church Slavonic: *аворъ (*avorŭ)
    • Church Slavonic: аворъ (avorŭ), ꙗворъ (javorŭ)
  • Bulgarian: я́вор (jávor), а́вор (ávor)
  • Macedonian: јавор (javor)
  • Serbo-Croatian:

    Cyrillic script: ја̏вор; јахор (dialectal)

    Latin script: jȁvor; jahor (dialectal)

  • Slovene: jávor (tonal orthography)
• West Slavic:
  • Kashubian: jawòr
  • Old Czech: javor
    • Czech: javor
  • Polabian: jovåră pl
  • Old Polish: jawor
    • Polish: jawor; jawór, jabór (dialectal)
      • → Vilamovian: jāwer
  • Slovak: javor
  • Sorbian:

    Lower Sorbian: jawor

    Upper Sorbian: jawor

• Non-Slavic:
  • → Lithuanian: jõvaras

• Vasmer, Max (1964–1973) “я́вор”, in Oleg Trubachyov, transl., Этимологический словарь русского языка [Etymological Dictionary of the Russian Language] (in Russian), Moscow: Progress
• Snoj, Marko (2016) “jávor”, in Slovenski etimološki slovar [Slovenian Etymology Dictionary] (in Slovene), 3rd edition, https://fran.si
• Králik, Ľubor (2016) “javor”, in Stručný etymologický slovník slovenčiny [Concise Etymological Dictionary of Slovak] (in Slovak), Bratislava: VEDA; JÚĽŠ SAV, →ISBN, page 242
• Rejzek, Jiří (2001) “javor”, in Český etymologický slovník [Czech Etymological Dictionary] (in Czech), 1st edition, Voznice: LEDA, →ISBN, page 252
• Boryś, Wiesław (2005) “jawor”, in Słownik etymologiczny języka polskiego (in Polish), Kraków: Wydawnictwo Literackie, →ISBN, page 208
• Melnychuk, O. S., editor (1982–2012), “я́вір”, in Етимологічний словник української мови [Etymological Dictionary of the Ukrainian Language] (in Ukrainian), Kyiv: Naukova Dumka