What does Zelda mean?
Commonly a short form of Griselda, from Germanic 'gris' (grey) and 'hild' (battle). A separate Yiddish name Zelda meaning roughly 'blessed/happy' also exists, so the battle sense specifically traces to the Griselda line.
What does Hildegard mean?
From Germanic 'hild' (battle) and 'gard' (enclosure, protection), roughly 'protector in battle'. Borne by the 12th-century abbess and polymath Hildegard of Bingen.