Nature

river

Source:*rěkaProto-Slaviccertain

The r before jat softened: Polish rz and Czech ř both come from it.

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English

river

Polish

rzeka

ˈʐɛka

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In all five languages

BCS script

Latin under Cyrillic

Russian
река́reka
rʲɪˈkainherited
Ukrainian
рі́чкаrička
ˈrʲitʃkainherited
A diminutive of ріка, which is also standard, mostly for big rivers.
Polish
rzeka
ˈʐɛkainherited
Czech
řeka
ˈr̝ɛkainherited
Bosnian-Croatian-Serbian
rijeka / rekaријека / река
ˈrijekainherited
Also the city of Rijeka, Italian Fiume ('river').
English
river