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
- Derksen, Rick (2008) Etymological Dictionary of the Slavic Inherited Lexicon (Leiden Indo-European Etymological Dictionary Series; 4), Leiden, Boston: Brill, ISBN 978 90 04 15504 6, page 25
- Trubačev O. N., editor (1974), “*a”, in Etimologičeskij slovarʹ slavjanskix jazykov [Etymological dictionary of Slavic languages] (in Russian), volume 01, Moscow: Nauka, page 33f
- J. Schaeken et al. Birchbark Literacy from Medieval Rus: Contents and Contexts (INTAS-Project Ref. Nr. 03-51-3867), document № 9.