Where does “четвъртък” come from?
четвъртък (Bulgarian) comes from Old Church Slavonic четврьтъкъ, from Proto-Slavic četvьrtъkъ, from Proto-Slavic četvьrtъ, from Proto-Balto-Slavic ketwirtas, from Proto-Indo-European *kʷetwr̥tós — fourth.
Ancestry of “четвъртък”, step by step
| Step | Language | Word | Meaning |
|---|---|---|---|
| 1 | Old Church Slavonic | четврьтъкъ | Thursday |
| 2 | Proto-Slavic | četvьrtъkъ | Thursday |
| 3 | Proto-Slavic | četvьrtъ | fourth |
| 4 | Proto-Balto-Slavic | ketwirtas | fourth |
| 5 | Proto-Indo-European | *kʷetwr̥tós | fourth |