Dictionary of Medieval Names
from European Sources

Ermengar m. Old High German ermen, Old Saxon irmin 'great, strong' + Old High German, Old Saxon gēr 'spear'.

France
Latin
c823 Ermengarius (nom) irminon-vol2 16, CE
Cite as: S.L. Uckelman. "Ermengar". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2017, no. 1. http://dmnes.org/2017/1/name/Ermengar.