masc. proper name, German Siegfried, first element from Old High German sigu "victory," from Proto-Germanic *seges- "victory" (source also of Old Frisian si, Old Saxon sigi, Middle Dutch seghe, Dutch zege, German Sieg, Old Norse sigr, Danish seier, Gothic sigis, Old English sige "victory, success, triumph"), from PIE root *segh- "to hold" (source also of Sanskrit saha- "victory," sahate "overcomes, masters").
Second element from Old High German frithu "peace" (from suffixed form of PIE root *pri- "to love"). Siegfried Line, World War I German fortifications in France, is from German Siegfriedlinie, named for the hero in Wagner's "Ring" cycle.