Dictionary of Medieval Names
from European Sources

Giselmund m. Old High German gīsal 'pledge, hostage' + Old Saxon mund, Old High German munt 'hand, protection'.

France
Latin
c823 Gislemundus (nom) irminon-vol2 18, CE
Cite as: S.L. Uckelman. "Giselmund". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Giselmund.