Circumflex on Lithuanian õ indicates a Proto-Indo-European long vowel (i.e. a lengthened grade) as the origin, as opposed to the short *e or *o with followed by a laryngeal.
According to the usual doctrine, the initial form was *h₁ōd, ablative singular of the PIE demonstrative pronoun *éy, h₁e. However, that demonstrative has no such ablative singular attested in any of the daughter languages, so that hypothesis remains unprovable.
- East Slavic:
- South Slavic:
- West Slavic:
- ^ E.g. Derksen 2008:25
- Rick Derksen (2008), Etymological Dictionary of the Slavic Inherited Lexicon, Brill: Leiden-Boston, page 25
- “*a” in Oleg Trubačóv (ed.) (1974–), Etimologičeskij slovarʹ slavjanskix jazykov [Etymological dictionary of Slavic languages], Moscow: Nauka, volume 01, page 33f