*nebh-

Proto-Indo-European root meaning "cloud."

It forms all or part of: nebula; nebular; nebulosity; nebulous; Neptune; Nibelungenlied; Niflheim; nimbus.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit nabhas- "vapor, cloud, mists, fog, sky;" Greek nephele, nephos "cloud;" Latin nebula "mist, vapor, fog, smoke, exhalation;" German Nebel "fog;" Old English nifol "dark, gloomy;" Welsh niwl "cloud, fog;" Slavic nebo.