Note: The reconstruction of *h₂elb^ho- with *h₂e is necessary as long as Indo-European a is not admitted, but nothing else appears to support the reconstruction. The etymon has been implicated in the Celtic derivative nominal base *albii̯o- "world," whence Welsh elfydd "world, earth, land, country" (Old Welsh elbid, Middle Welsh eluit) and the Gaulish divine name Albiorīx, literally, "world-king." According to this hypothesis, *albii̯o- forms a counterpart to Celtic *dubno- (> *dumno-) "world," whence Old Irish domun "world," Gaulish Dumnorīx, a personal name, literally, "world-king." Originally these two etyma would have denoted distinct entities, *albii̯o-, from *alb^ho- "white," being the lighter, brighter upper world (compare semantically Old Church Slavic světŭ "light, world"); *dubno-, on the other hand, nominalized from the adjective *dubno- "deep" (whence Old Irish domain "deep," Welsh dwfn), denoted the depths of the earth and bodies of water (see deep entry 1). Attempts have been made, with varying degrees of acceptance, to link *alb^ho- "white" with other etyma, as a Germanic and Slavic word for "swan" (Old English aelbitu [Corpus and Epinal glossaries], ylfetu, Middle High German albiz, elbiz, Old Icelandic ǫlpt, genitive alptar, Russian lébedʼ, Polish łabędź, Bosnian-Croatian-Serbian lȁbūd); also with a variety of geographical names, as Latin Albis "the river Elbe" and other river names (compare Old Icelandic elfr "river," Danish elv, Swedish älv), Latin Alpēs "the Alps"; and with Germanic *albi-, *alba-, name of a mythological being (see elf).