Nav (Croatian,Czech,Slovak:Nav,Polish:Nawia,Russian:Навь,Serbian:Нав,Slovene:Navje,Ukrainian:Мавка,Mavka orНявка,Nyavka)[a] is a phrase used to denote thesouls of the dead inSlavic mythology. The singular form (Nav orNawia) is also used as a name for anunderworld, over whichVeles exercises custody—it is often interpreted as another name for the underground variant of theVyraj (heaven orparadise).[3]
The wordsnawia,nav and its other variants are most likely derived from theProto-Slavic*navь-, meaning "corpse", "deceased".[4] Cognates in otherIndo-European languages includeLatviannāve ("death"),Lithuaniannõvis ("death"),Old Prussiannowis ("body, flesh"),Old East Slavicнавь (navʹ) ("corpse, dead body") andGothic𐌽𐌰𐌿𐍃 (naus, "dead body, corpse").[5]

Thenawie,nawki, sometimes also referred to aslalki[3] (Polish language; all plural forms) were used as names for the souls of the dead. According to some scholars (namelyStanisław Urbańczyk, among others), this word was a general name for demons arising out of the souls of tragic and premature deaths, killers, warlocks, the murdered and theDrowned Dead.[6] They were said to be hostile and unfavourable towards humans, being jealous of life.[6] InBulgarian folklore there exists the character of 12navias that sucked the blood out of women giving birth, whereas in the RuthenianPrimary Chronicle thenavias are presented as a demonic personification of the 1092 plague inPolotsk.[4] According to folk tales, thenawie usually took the form of birds.[3]
The phraseNawia (Polish) orNav (used across Slavic tongues) was also utilised as a name for the Slavonic underworld, ruled by the godVeles, enclosed away from the world either by a living sea or river, according to some beliefs located deep underground.[3] According to Ruthenian folklore, Veles lived on a swamp in the centre of Nav, where he sat on a golden throne at the base of theCosmic Tree, wielding a sword.[3] Symbolically, the Nav has also been described as a huge green plain—pasture, onto which Veles guidessouls.[3] The entrance toNav was guarded by aZmey.[3] It was believed the souls would later bereborn on earth.[7] It is highly likely that these folk beliefs were the inspiration behind the neopagan idea ofJav, Prav and Nav in the literary forgery known as theBook of Veles.