Where does “обоюдоострый” come from?

обоюдоострый (Russian) comes from Russian о́стрый, from Proto-Slavic ostrъ, from Proto-Balto-Slavic aśras, from Proto-Indo-European *h₂eḱrós, from Proto-Indo-European h₂eḱ- — sharp.

обоюдоострый (Russian): double-edged

Definitions

  1. double-edged

Ancestry of “обоюдоострый”, step by step

обоюдоострый traces back through two separate lines of ancestry.

via Russian о́стрый

StepLanguageWordMeaning
1Russianо́стрыйpointed, sharp; sharp, pointed
2Proto-Slavicostrъsharp
3Proto-Balto-Slavicaśrassharp
4Proto-Indo-European*h₂eḱróssharp
5Proto-Indo-Europeanh₂eḱ-sharp

via Russian обою́дный

StepLanguageWordMeaning
1Russianобою́дныйmutual, reciprocal
Every word from Proto-Indo-European h₂eḱ-Every word from Proto-Indo-European *h₂eḱrósEvery word from Proto-Balto-Slavic aśras