*Perkʷūnos
In a widespread Indo-European myth, the thunder-deity fights a multi-headed water-serpent during an epic battle in order to release torrents of water that had previously been pent up.
Contrary to other deities of the Proto-Indo-European pantheon, such as *Dyēus (the sky-god), or *H2éwsōs (the dawn-goddess), widely accepted cognates stemming from the theonym *Perkʷūnos are only attested in Western Indo-European traditions.
[4] Various cognates can be found in the Latin oak-nymphs Querquetulanae (from quercus 'oak-tree'),[2][5] the Germanic *ferhwaz ('oak'),[6] the Gaulish erc- ('oak') and Quaquerni (a tribal name),[7][5] the Punjabi pargāi ('sacred oak'),[8] and perhaps in the Greek spring-nymph Herkyna.
[11][12] A theory uniting those two etymologies has been proposed in the mythological association of oaks with thunder, suggested by the frequency with which such tall trees are struck by lightning.
[3][16] Other Indo-European theonyms related to 'thunder', through another root *(s)tenh₂-, are found in the Germanic Þunraz (Thor), the Celtic Taranis (from an earlier *Tonaros), and the Latin epithet Tonans (attached to Jupiter).
[17][18] According to scholar Peter Jackson, "they may have arisen as the result of fossilization of an original epithet or epiclesis" of Perkwunos, since the Vedic weather-god Parjanya is also called stanayitnú- ("Thunderer").
[11] Perkwunos is usually depicted as holding a weapon, named *meld-n- in the Baltic and Old Norse traditions, which personifies lightning and is generally conceived as a club, mace, or hammer made of stone or metal.
In different Albanian regions, for rainmaking purposes, people threw water upwards to make it subsequently fall to the ground in the form of rain.
In the Albanian language, a word to refer to the lightning—considered in folk beliefs as the "fire of the sky"—is shkreptimë, a formation of shkrep meaning "to flash, tone, to strike (till sparks fly off)".
[38][6][7] The Old Russian chronicles describes wooden idols of Perūn on hills overlooking Kiev and Novgorod, and both the Belarusian Piarun and the Lithuanian Perkūnas were said to dwell on lofty mountaintops.
Such places are called perkūnkalnis in Lithuanian, meaning the "summit of Perkūnas", while the Slavic word perynja designated the hill over Novgorod where the sanctuary of Perun was located.
[34][40] Words from a stem *pér-ur- are also attested in the Hittite pēru ('rock, cliff, boulder'),[41] the Avestan pauruuatā ('mountains'),[42] as well as in the Sanskrit goddess Parvati and the epithet Parvateshwara ('lord of mountains'), attached to her father Himavat.
[52] A common practice was to hang a thunder-stone pendant on the body of the cattle or on the pregnant woman for good luck and to counteract the evil eye.
[55][47][56] Scholars have also noted that Perkūnas and Piarun are said to strike rocks instead of oaks in some themes of the Lithuanian and Belarusian folklores,[57] and that the Slavic Perūn sends his axe or arrow from a mountain or the sky.
[58] The following deities are cognates stemming from *Perkwunos or related names in Western Indo-European mythologies: The name of Perkwunos' weapon *meld-n- is attested by a group of cognates alternatively denoting 'hammer' or 'lightning' in the following traditions: Another PIE term derived from the verbal root *melh₂- ('to grind'), *molh₁-tlo- ('grinding device'), also served as a common word for 'hammer', as in Old Church Slavonic mlatъ, Latin malleus, and Hittite malatt ('sledgehammer, bludgeon').
[133][134] Places in South-Slavic-speaking lands are considered to be reflexes of Slavic god Perun, such as Perunac, Perunovac, Perunika, Perunićka Glava, Peruni Vrh, Perunja Ves, Peruna Dubrava, Perunuša, Perušice, Perudina, and Perutovac.
[136] Patrice Lajoye associates place names in the Balkans with the Slavic god Perun: the city of Pernik and the mountain range Pirin (in Bulgaria).
