Where does “пятый” come from?

пятый (Russian) comes from Old East Slavic пѧтъ, from Proto-Slavic pętъ, from Proto-Balto-Slavic penktas, from Proto-Hellenic penkʷtos, from Proto-Indo-European pénkʷe — five.

пятый (Russian): fifth

Definitions

  1. fifth

Ancestry of “пятый”, step by step

StepLanguageWordMeaning
1Old East Slavicпѧтъfifth
2Proto-Slavicpętъfifth
3Proto-Balto-Slavicpenktasfifth
4Proto-Hellenicpenkʷtos—
5Proto-Indo-Europeanpénkʷefive
Every word from Proto-Indo-European pénkʷe →Every word from Proto-Hellenic penkʷtos →Every word from Proto-Balto-Slavic penktas →