Geltrude is the Italian form of Gertrude — Old German ger (spear) and trud (strength), "spear-strength." Saint Gertrude the Great (1256-1302) was the German Cistercian mystic.
Suor Gertrude appears in Manzoni's The Betrothed (1827).
Geltrude reduces to six — the number of Italian Gertrude.