Dictionary of Medieval Names
from European Sources

Gilmar m. Old High German gīsal 'pledge, hostage' + Old High German, Old Saxon māri from Proto-Germanic *mērijaz 'famous'.

France
Latin
c823 Gislemar (nom) irminon-vol2 28, Wan; 1147 Giselmarus (nom) clairvaux-12thc 18
Cite as: S.L. Uckelman. "Gilmar". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Gilmar.