Where does “третья” come from?

третья (Russian) comes from Russian тре́тий, from Old East Slavic треть, from Proto-Slavic tretь, from Proto-Balto-Slavic tretias, from Proto-Balto-Slavic tirtias, from Proto-Indo-European tr̥tyos, from Proto-Indo-European *tréyes.

третья (Russian): third

Definitions

  1. third

Ancestry of “третья”, step by step

StepLanguageWordMeaning
1Russianтре́тийthird
2Old East Slavicтретьthird
3Proto-Slavictretьthird
4Proto-Balto-Slavictretias—
5Proto-Balto-Slavictirtias—
6Proto-Indo-Europeantr̥tyos—
7Proto-Indo-European*tréyes—
Every word from Proto-Indo-European *tréyes →Every word from Proto-Indo-European tr̥tyos →Every word from Proto-Balto-Slavic tirtias →