masc. proper name, German Siegfried, first element from Old High German sigu "victory," from Proto-Germanic *sigiz- "victory" (cf. 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 have, to hold" (cf. Sanskrit saha- "victory," sahate "overcomes, masters;" see scheme (n.)).
Second element from Old High German frithu "peace," from PIE *pri-tu-, from root *pri- "to love" (see free (adj.)). Siegfried Line, World War I German fortifications in France, is from German Siegfriedlinie, named for the hero in Wagner's "Ring" cycle.