Reconstruction:Proto-Slavic/buky

Of Germanic origin, with two proposed sources of borrowing:

• For meaning beech: From Proto-West Germanic *bōku (“beech”),[1][2] formally equivalent to *bukъ (“beech”) +‎ *-y.
• For meaning books, writs: From Gothic 𐌱𐍉𐌺𐍉𐍃 pl (bōkōs, “books”) (per Vasmer, Trubachev).

Interrelation between the two meanings is now widely considered uncertain (or even dismissed entirely, e.g. by Kluge/Seebold), mainly because there is no surviving evidence for beech-based writing among early Germanic and Balto-Slavic peoples. It is possible (as noted by Mallory and Adams) that beech had religious significance for ancient Indo-European people and so was used to inscribe sacred symbols onto[2]. In this case, the extended meaning writ, sign would be directly borrowed from Germanic. A third hypothesis speculates that beechmast was used for counting and bookkeeping, whence the word innately developed a sense of “unit of data representation” → grapheme, writ.

*bùky f[3][1]

1. Alternative form of *bukъ (“beech”)
2. (by specialization) beechmast
3. (by extension) writ, grapheme, written sign → letter

   Synonyms: *čьrka, *pisьmo, *znakъ

4. (by extension, in the plural) books (corpus of written inscriptions)

   Synonym: *kъňigy

The meaning in West and Western South Slavic is beech or beechmast, while in East and Eastern South Slavic, the primary attested meaning is letter (or generally grapheme). It has evolved from an earlier meaning inscription, writ (attested in Church Slavonic). Occassionally, Old Church Slavonic боукъви pl (bukŭvi) could also refer to tally or another bookkeeping mean.

During the development of Church Slavonic writing, Old Church Slavonic боукꙑ (buky) was chosen as the name for the second letter of the Cyrillic and Glagolitic alphabets, whence the term азъбоукꙑ (azŭbuky, “alphabet”).

• *bukъvařь (“alphabet textbook”)
• *bukъvica (“beechmast; small letter”)

• *bukъ (“beech”)

• East Slavic:
  • Old East Slavic: бꙋкꙑ (buky), бꙋкъвь (bukŭvĭ), бꙋкъва (bukŭva)
    • Russian: бу́ква (búkva), бу́ки (búki)
      • → Ingrian: bukva
      • → Polish: bukwa
      • → Skolt Sami: bukva
    • Carpathian Rusyn: бу́ква (búkva)
    • Ukrainian: бу́ква (búkva)
• South Slavic:
  • Old Church Slavonic:

    Cyrillic: боукꙑ (buky)

    Glagolitic: ⰱⱆⰽⱏⰺ (buky)

    • → Romanian: buche
  • Bulgarian: бу́ква (búkva)
  • Macedonian: буква (bukva)
  • Serbo-Croatian:

    Cyrillic script: бу̏ква

    Latin script: bȕkva

  • Slovene: bȗkəv, bȗkva (tonal orthography)
• West Slavic:
  • Old Czech: bukev
    • Czech: bukva, bukev
  • Polabian: bükvoi
  • Old Polish: bukiew
    • Polish: bukiew
  • Slovak: bukev
  • Slovincian: búkwa
  • Sorbian:
    • Upper Sorbian: bukow

• Vasmer, Max (1964–1973) “буква”, in Oleg Trubachyov, transl., Этимологический словарь русского языка [Etymological Dictionary of the Russian Language] (in Russian), Moscow: Progress
• Trubachyov, Oleg, editor (1976), “*buky”, in Этимологический словарь славянских языков [Etymological dictionary of Slavic languages] (in Russian), numbers 3 (*bratrьcь – *cьrky), Moscow: Nauka, page 91
• Sławski, Franciszek, editor (1974), “*buky”, in Słownik prasłowiański [Proto-Slavic Dictionary] (in Polish), volumes 1 (a – bьzděti), Wrocław: Ossolineum, page 446
• Georgiev, Vladimir I., editor (1971), “буква”, in Български етимологичен речник [Bulgarian Etymological Dictionary] (in Bulgarian), volumes 1 (А – З), Sofia: Bulgarian Academy of Sciences Pubg. House, →ISBN, page 87
• Skok, Petar (1971) “Proto-Slavic/buky”, in Etimologijski rječnik hrvatskoga ili srpskoga jezika [Etymological Dictionary of the Croatian or Serbian Language] (in Serbo-Croatian), volumes 1 (A – J), Zagreb: JAZU, page 230
• Verweij, Arno (1994) “Quantity Patterns of Substantives in Czech and Slovak”, in Dutch Contributions to the Eleventh International Congress of Slavists, Bratislava (Studies in Slavic and General Linguistics)‎, volume 22, Editions Rodopi B.V., page 520