The Pronia (Belarusian: Проня, Russian: Проня, also transliterated as Pronya) is a river in Mogilev and Vitebsk regions of Belarus. A right tributary of Sozh River, the Pronia begins near the village of Lanenka, Dubrowna District, Vitebsk Oblast. It flows from north to south, joining the Sozh in the eastern outskirts of the city of Slavgorod.[1]
According to Max Vasmer, the name Pronya is associated with the Czechproný (fast, indomitable), in turn, possibly, arising from the Czech prudký (fast, compare with the Russian word prud).[2]
According to Vladimir Toporov and Oleg Trubachyov, the name of the Pronia has Baltic origins. They propose that this hydronym evolved as follows: *Piren –(Baltic) – *Prena – *Pryona – Prornya. This correlates with the names of the Peranka, Perenka, Perinka, Piryanka rivers, which lie in the Sozh basin near the Pronya. Accordingly, the river is called the Pirėnai in Lithuanian or the Piranen, Piron in the Ancient Prussian.[3]
Earlier, together with the modern name the river was also called the Propoy, also referring to its fast flow. The name of the city of Propoysk, renamed Slavgorod in 1945, arose from this term.[4]

According to legend, the name arises from a girl named Basya and a youth named Pronya who lived nearby, who were in love with each other. Pronya was a poor peasant, and therefore Basya's parents were against their wedding. The lovers decided to flee, but were pursued. Not managing to elude their pursuers, the couple wished for the gods to grant them a future together. When the girl's father reached the glade, he saw the confluence of two rivers, which turned into the Basya and Pronya.[5]
Another legend tells that the Pronya was named for a Romani girl who drowned in the river.[6]
プロニャ川の源流は、ヴィテプスク州ドゥブロヴナ地区ラネンカ村近郊のスモレンスク高地にある。この川はオルシャ・モギリョフ平原を流れ、スラハラド市の近くで右からソジ川に合流する。[ 7 ]
この川は 全長172km、流域面積は4,910km2です。河口での流量は平均30m3/sです。[ 8 ]河川表面の平均勾配は0.5%ですが、場所によっては2~2.5%まで上昇します。[ 1 ] [ 9 ]