1) From middle Old Terran cultures, the Germanic form of Sigurd (Old Norse: Sigurðr), a legendary hero of Norse mythology, 2) The third of the four operas that constitute The Ring of the Nibelung by Old Terran composer, Richard Wagner. 3) The one-name moniker by which “those in the know” in the civilized Multiverse knew Siegfried “McMauMau” Siegfriedson (See: Siegfriedson, Siegfried “McMauMau”).