Reconstruction:Proto-Slavic/osojь

Unclear: denominal/deverbal, *ot-/*ob-, *(s)ḱeh₁y-/*(s)ḱeh₃-.

*ob-/*ot-:

• Per Miklosich, Дуриданов, Лома: from *otsojь with *ot-. Compare 13th century Old Serbian на Ѡтсоиноу стѣноу[1] and antonymous Church Slavonic присоѥ (prisoje, “sunny place”).[2]
• Per ESSJa: from *obsojь with "shadow" ⇐ "shine" / "reflection" (отблеск). Compare Sanskrit छाया (chāyā, “shadow; shade; reflection”) ("shadow" ⇒ "reflection" if from *(s)ḱeh₃- (“darkness, shadow”)).
  • Proto-Slavic *ob (“around”) would mean one around which light passes, devoid of light. Similar to Proto-Slavic *ostrovъ (“island”) from Proto-Slavic *strujiti (“to stream”).
• Per Bezlaj: from *obsojь with abessive *ob-. Compare *h₂epó (“off, away”) / *h₂pó > *opakъ, *po.
• Per Skok: from assimilated *usojь, from negative *u-. Compare *ubogъ.

*(s)ḱeh₁y-/*(s)ḱeh₃-:

• Proto-Indo-European *(s)ḱeh₁y- (“to shine, shimmer”)
  • *sijati (“to shine”) (per ESSJa, BER)
  • Gothic 𐍃𐌺𐌴𐌹𐌽𐌰𐌽 (skeinan, “to shine”) (per ?ESSJa, ?Vasmer)
• *(s)ḱeh₃y- (“to shade”), *(s)ḱeh₃-
  • Proto-Slavic *sěnь (“shadow”) (per Vasmer). See also *siňь, *sivъ, *śěrъ.
  • Ancient Greek σκιά (skiá, “shadow; shade”), σκοιός (skoiós, “shady”) (per ?ESSJa, ?Vasmer)
  • Sanskrit छाया (chāyā, “shadow; shade; reflection”) (per ?ESSJa, ?Vasmer)
• See also Proto-Germanic *blakaz and *blaikaz, *blankaz.

*osòjь m[3]

1. shady place

• *osoja f
• *osoje n

• *sěnь (“shadow”)
• *sivъ, *śěrъ, *śědъ (“gray”)
• *soja, *sojьka (“jay”)

• *osojьnъ, *usojьnъ (“shady, non-lit by the sun”)
  • *osojьnikъ, *usojьnikъ (“flower growing in shady places, Echium”)
  • *osojьnica, *usojьnica (“viper”) (lit. one that rests at shady places)
• *osojьskъ (“northern, non-lit by the sun”)

• East Slavic:
  • Ukrainian: осовня (osovnja) (dialectal)
• South Slavic:
  • Old Church Slavonic: осои (osoi), осоѥ (osoje)
  • Bulgarian: осо́й (osój), осо́я (osója), осо́е (osóe); усо́й (usój), усо́йна (usójna)
  • Macedonian: осој (osoj)
  • Serbo-Croatian:

    Cyrillic script: осојe

    Latin script: osoje

  • Slovene: osọ̄ja, osóje
    • ⇒ Slovene: osóvje, osónje

• Trubachyov, Oleg, editor (2002), “*obsoja/*obsoje/*obsojь”, in Этимологический словарь славянских языков [Etymological dictionary of Slavic languages] (in Russian), numbers 29 (*obpovědati – *obsojьnica), Moscow: Nauka, →ISBN, page 251
• Georgiev, Vladimir I., Duridanov, I. V., editors (1995), “осой, осоя, осое”, in Български етимологичен речник [Bulgarian Etymological Dictionary] (in Bulgarian), volumes 4 (мѝнго² – па̀дам), Sofia: Prof. Marin Drinov Pubg. House, →ISBN, page 942
• Vasmer, Max (1964–1973) “сиять”, in Oleg Trubachyov, transl., Этимологический словарь русского языка [Etymological Dictionary of the Russian Language] (in Russian), Moscow: Progress