Where does “Irkuck” come from?

Irkuck (Polish) comes from Russian Ирку́тск, from Russian -ск, from Proto-Slavic -ьskъ, from Proto-Indo-European -iskos — Characteristic of, typical of, pertaining to.

Ancestry of “Irkuck”, step by step

StepLanguageWordMeaning
1RussianИрку́тск—
2Russian-скA suffix used in place names
3Proto-Slavic-ьskъ-ic, -ish
4Proto-Indo-European-iskosCharacteristic of, typical of, pertaining to
Every word from Proto-Indo-European -iskos →Every word from Proto-Slavic -ьskъ →Every word from Russian -ск →