Reconstruction:Proto-Slavic/čьrtъ

Unclear. Usually two theories are proposed:

• Past passive participle of unattested verb (nouns: *čarъ, *čara (“magic, sorcery”)) that is the exact equivalent of the Lithuanian kerė́ti (“to bewitch”). This etymology is supported by analogies, cf. *vȏrgъ (“foe, enemy; evil spirit”) > *voržiti (“to divine”). Cognate with Sanskrit कृत्या (kṛtyā, “female demon, sorceress”).
• Past passive participle of *čerti (“to cut”). This etymology is supported by the fact that in many beliefs, evil spirits were often mutilated, cf. Polish kusy (“devil”), Bulgarian къ́с (kǎ́s, “devil”) from Proto-Slavic *kǫsъ (“bitten off; short; tailless”). Relation with *čьrta, *čara (“line”), *čersti, *čьrtiti (“to cut”) is also possible.

Other propositions include:

• Berneker: past passive participle of unattested verb that is the exact equivalent of the Lithuanian kyrė́ti (“to take revenge”) from Proto-Indo-European *(s)ker- (“to turn, to cross”) (or *ker- (“to assault”)) with literal meaning “avenger”. Bezlaj derives it from the same root, but through a different semantic shift: “astride, askew” → “evil, treacherous”.
• From Proto-Indo-European *(s)kerH- (“to swing, to skip, to jump”) though a semantic development “quick” → “scary, freakish”.

Modern descendants are sometimes associated through folk etymology with (descendants of) Proto-Slavic *čьrnъ (“black”).

*čь̑rtъ m[1][2][3][4]

1. demon, devil, evil creature

   Synonym: *běsъ

2. (possibly) enemy, foe[2]

   Synonym: *vorgъ

• *čьrtiti, *čьrtovati (“to carouse, to do evil”)
• *čьrtьcь (diminutives)
• *čьrtovъ, *čьrtьjь (relative adjectives)

• East Slavic:
  • Old East Slavic: чортъ (čortŭ)
    • Belarusian: чорт (čort)
    • Russian: чёрт (čort)
      • → Bulgarian: чорт (čort)
      • → Polish: czort
    • Ukrainian: чорт (čort)
• South Slavic:
  • Slovene: čȓt (“hostile spirit; animosity”)
• West Slavic:
  • Old Czech: črt
    • Czech: čert
      • → Polish: czert
      • Moravian (Mistřice): čert
  • Kashubian: czart
  • Polish: czart
  • Slovak: čert
  • Slovincian: čãrṭ
  • Sorbian:
    • Lower Sorbian: cart; cert (dialectal)
    • Upper Sorbian: čert

• Non-Slavic:
  • → Lithuanian: čartas, čertas

• Vasmer, Max (1964–1973), “чёрт”, in Этимологический словарь русского языка [Etymological Dictionary of the Russian Language] (in Russian), transl. and suppl. by Oleg Trubachyov, Moscow: Progress
• “skėrys”, in Lietuvių kalbos etimologinio žodyno duomenų bazė [Lithuanian etymological dictionary database], 2007–2012
• Melnychuk, O. S., editor (1982–2012), “чорт”, in Етимологічний словник української мови [Etymological Dictionary of the Ukrainian Language] (in Ukrainian), Kyiv: Naukova Dumka
• Марр, Н. Я. (1924), “Название этрусского бога смерти Kalu и термины ‘писать’, ‘петь’, ‘чорт’, 'поэт' и ‘слепец’”, in Известия Российской Академии Наук. VI серия‎ (in Russian), volume 18, issue 1–11, page 188 of 183–194, compares to Old Georgian ჭორტი (č̣orṭi, “stone statue; cairn”), which appears to be connected to Old Ossetic τζηρθε (tzērthe, “stele, monument”)