Latin Etymology Borrowed from Ancient Greek πυρήν (purḗn). Noun pȳrēn f (genitive pȳrēnis); third declension An unknown kind of precious stone Declension Third-declension noun.More information singular, plural ... singular plural nominative pȳrēn pȳrēnēs genitive pȳrēnis pȳrēnum dative pȳrēnī pȳrēnibus accusative pȳrēnem pȳrēnēs ablative pȳrēne pȳrēnibus vocative pȳrēn pȳrēnēs Close References “pyren”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press pyren in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette. Swedish Noun pyren indefinite plural of pyreWikiwand - on Seamless Wikipedia browsing. On steroids.