фир

Unclear. Compare Proto-Slavic *pyrь (“cinder, incense; lye”), reflected in dialectal пирива́ (pirivá, “poor-quality soil”), or loanword фира́ (firá, “lees, sludge, residue”) (borrowed from Greek φύρα (fýra, “waste”)).

• IPA^(key):

фир • (fir) m

1. (dialectal, dated) soak, ooze, pickle (acrid, bitter substance used in the past to distill grain or other raw food)

   Synonyms: (partially) квас (kvas), (dialectal) цад (cad)

   → (by extension) container, bag, vessel for implementing zymurgy

2. (figurative, colloquial) home-made spirit, alcohol, booze

   Synonyms: (standard terms) спирт (spirt), алкохо́л (alkohól)

• фур (fur)

• фи́рувам (fíruvam, “to ferment, to soak in фир”)
• фи́ркам (fírkam, “to drink alcohol, to booze”) (slang)
  • фиркаджи́я (firkadžíja, “drunkard”)

• оло́вина (olóvina, “ale”) (product made via фируване)

• Nayden Gerov, Тодор Панчев (1904) “фуръ”, in Рѣчникъ на Блъгарскꙑй язꙑкъ. Съ тлъкувание рѣчи-тꙑ на Блъгарскꙑ и на Русскꙑ. [Dictionary of the Bulgarian language]‎ (in Bulgarian), volume 5, Plovdiv: Дружествена печꙗтница "Съгласие.", page 477