(муња), Slovene mółnja, Bulgarian: , Macedonian: молња, 'lightning', Russian: mólnija (молния), 'lightning', Ukrainian maladnjá (dial.) 'lightning without thunder', Belarusian: маланка, 'lightning', Czech: (arch.), Polish (dial.), Lusatian: milina (arch.) 'lightning' (modern 'electricity'), Baltic: *mildnā, Old Prussian: , 'lightning bolt', Latvian: milna, the 'hammer of the Thunderer', Pērkōns, Celtic: *meldo-, Gaulish: Meldos, an epithet of thunder divinity Loucetios; as well as Meldi (*Meldoi), a tribal name, and Meldio, a personal name. Welsh: , 'lightning, thunderbolts' (sing. , 'bolt of lightning'), and Mabon am Melld or Mabon fab Mellt ('Mabon son of Mellt'), Breton: mell, 'hammer', Middle Irish: mell, 'rounded summit, small hill', possibly via semantic contamination from , '(wooded) mountains'. Armenian: մուրճ (mowrtch), 'hammer'. Another PIE term derived from the verbal root ('to grind'), ('grinding device'), also served as a common word for 'hammer', as in Old Church Slavonic mlatъ, Latin malleus, and Hittite malatt ('sledgehammer, bludgeon'). 19th-century scholar Francis Hindes Groome cited the existence of the "Gypsy" (Romani) word malúna as a loanword from Slavic molnija. The Komi word molńi or molńij ('lightning') has also been borrowed from Slavic. Heavenly vault of stone PIE: *h₂eḱ-, 'sharp', PIE: *h₂éḱmōn (gen. *h₂ḱmnós; loc. *h₂ḱméni), 'stone, stone-made weapon' > 'heavenly vault of stone', Indo-Aryan: *Haćman, Vedic: áśman, 'stone, sling-stone, thunderbolt', Avestan: asman, 'stone, sling-stone, heaven', Greek: ákmōn (ἄκμων), 'anvil, meteoric stone, thunderbolt, heaven', Balto-Slavic: *akmen-, Lithuanian: akmuõ, 'stone', Latvian: akmens, 'stone', Germanic: *hemō (gen.*hemnaz, dat. *hemeni), 'heaven', Gothic: himins, 'heaven', Old English: heofon, Old Frisian: himel, Old Saxon: heƀan, Old Dutch: himil, Old High German: himil, 'heaven', Old Norse: himinn, 'heaven', A metathesized stem *ḱ(e)h₂-m-(r)- can also be reconstructed from Slavic *kamy ('stone'), Germanic *hamaraz ('hammer'), and Greek kamára ('vault'). Other possible cognates Indo-Iranian: Vedic: Parjanya, the god of rain, thunder and lightning (although Sanskrit sound laws rather predict a form; an intermediate form *pergénio has therefore been postulated, possibly descending from *per-kwun-iyā). Nuristani: Pärun (or Pērūneî), a war god worshipped in Kafiristan (present-day Nuristan Province, Afghanistan), Persian: Piran (Viseh), a heroic figure present in the Shahnameh, the national epic of Greater Iran; it has been suggested his name might be related to the Slavic deity Perun, Scythian: in the 19th century, Russian folklorist Alexander Afanasyev and French philologist Frédéric-Guillaume Bergmann (fr) mentioned the existence of a Scythian deity named Pirkunas or Pirchunas, an epithet attached to the "Scythian Divus" and meaning 'rainy'. Celtic ('oak'), Hispano-Celtic: Erguena (ERGVENA), a personal name thought to mean