Reconstruction:Proto-Slavic/kъsьnъ

This Proto-Slavic entry contains reconstructed terms and roots. As such, the term(s) in this entry are not directly attested, but are hypothesized to have existed based on comparative evidence.

Per Derksen, from Proto-Balto-Slavic *kuśnas, probably continuing an obscure Proto-Indo-European *kewḱ-. Cognate with Latvian kusls (“stiff, small, weak”), Lithuanian kùšlas (“blind, weak, small”).

Trubachev proposes instead a connection to Proto-Slavic *kysělъ (“sour, bitter”) (or Proto-Slavic *kvasъ (“leaven”) in that matter) via semantic shift sour → overpassed its expiration date → late similar to Latin sērus (“late”) from Latin serum (“whey”).

Technically, could also reflect an earlier *kъtsьnъ akin to Proto-Slavic *kъsenь (“caviar, spawn”), Proto-Slavic *kutiti (“to push”), Proto-Slavic *kustriti (“to push, to incite”) and further Lithuanian kùtas (“fringe, hem”). Per Snoj, ultimately from Proto-Indo-European *kweh₂t- (“to seethe”), probably a t-extension of Proto-Indo-European *kewh₂- (“to hew”).

*kъ̀sьnъ

1. slow, late

   Synonym: *pozdьnъ

• *kъsьno (“late”) (adverb)
• *kъsьněti (“to be late”)

• South Slavic:
  • Old Church Slavonic: късьнъ (kŭsĭnŭ), къснъ (kŭsnŭ)
    • → Belarusian: косны (kósny)
    • → Russian: ко́сный (kósnyj)
    • → Ukrainian: ко́сний (kósnyj)
  • Bulgarian: къ́сен (kǎ́sen)
  • Macedonian: касен (kasen) (dialectal)
  • Serbo-Croatian:

    Cyrillic script: ка̏сан

    Latin script: kȁsan

  • Slovene: kəsȃn (tonal orthography), kásen

• Vasmer, Max (1964–1973) “ко́сный”, in Oleg Trubachyov, transl., Этимологический словарь русского языка (in Russian), Moscow: Progress
• Trubachyov, Oleg, editor (1987), “*kъsьnъ(jь)”, in Этимологический словарь славянских языков (in Russian), numbers 13 (*kroměžirъ – *kyžiti), Moscow: Nauka, page 246
• Georgiev, Vladimir I., editor (1986), “късен”, in Български етимологичен речник (in Bulgarian), volume 3 (крес¹ – мѝнго¹), Sofia: Bulgarian Academy of Sciences Pubg. House, page 229