norwegium

from The Century Dictionary.

• noun Chemical symbol, Ng. A supposed metallic element closely related to bismuth. Its properties have not been fully investigated nor its elementary nature fully established.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) A rare metallic element, of doubtful identification, said to occur in the copper-nickel of Norway. Not recognized as an element (1999).

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun obsolete A rejected name for hafnium.