Dictionary of Medieval Names
from European Sources

Giselhar m. Old High German gīsal 'pledge, hostage' + Old High German heri 'host, army'.

France
Latin
c823 Gisleharius (nom) irminon-vol2 51
Cite as: S.L. Uckelman. "Giselhar". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2017, no. 1. http://dmnes.org/2017/1/name/Giselhar.