Bahuvrihi adjectives *ubogъ (“poor, miserable”) and *nebogъ (“poor, miserable”), as well as the later derivation *bogatъ (“rich”) prove that *bogъ was originally also an adjective meaning "earthly wealth/well-being; fortune", with a semantic shift to "dispenser of wealth/fortune" and finally "god". Semantic parallel can be drawn to Indo-Iranian languages: compare Old Persian 𐏎 (baga, “god”), Avestan [script needed] (baγa-, “god”) (but also [script needed] (bag-, “apportion”)), as well as Sanskrit epithet often applied to gods भग (bhaga, “dispenser, gracious lord, patron”), proving that Slavic noun had both abstract and concrete meanings. The same Iranian source, but via a Turkic language, also probably gave Proto-Slavic *banъ.
This convincing parallel has led some linguists (e.g. Roman Jakobson) to claim that *bogъ is an Iranian borrowing. Slavic-Iranian parallelism can be further extended to the expressions of Slavic mythology: Dažbog, Belobog and Chernobog, which prove an existence of Iranian dualism in Proto-Slavic mythology.
Some connect it to Ancient Greek ἔφαγον (éphagon, “to eat, devour”) via a semantic shift "I received a share" > "I consumed" > "I ate". This would in turn all derive from the Proto-Indo-European root *bʰeh₂g-, *bʰag- (“to distribute, divide”).
*bȏgъ m (accent paradigm c)
- East Slavic:
- South Slavic:
- West Slavic:
- Rick Derksen (2008), Etymological Dictionary of the Slavic Inherited Lexicon, Brill: Leiden-Boston, page 50
- “*bogъ” in Oleg Trubačóv (ed.) (1974–), Etimologičeskij slovarʹ slavjanskix jazykov [Etymological dictionary of Slavic languages], Moscow: Nauka, volume 02, page 161
- Petar Skok (1971), Etimologijski rječnik hrvatskoga ili srpskoga jezika, Zagreb: JAZU, volume I, page 178ff
- J. P. Mallory, D. Q. Adams (eds.) (1997), Encyclopedia of Indo-European culture, London: Fitzroy Dearborn Publishers, page 161
- Robert S. P. Beekes (2010) Etymological Dictionary of Greek, Leiden, Boston: Brill Academic Publishers, volume II, page 1543
- Helmut Rix (ed.) (2001), Lexikon der indogermanischen Verben (second edition), Wiesbaden: Dr. Ludwig Reichert Verlag, page 65
- “бог” in Max Vasmer (1986), Etimologičeskij slovarʹ russkogo jazyka [Etymological Dictionary of the Russian Language], in 4 vols (second edition), Moscow: Progress — Translated from German and supplemented by O. N. Trubačóv