Dictionary of Medieval Names
from European Sources

Gerhaus f. Old High German, Old Saxon gēr 'spear' + Old High German hadu 'battle'.

France
Latin
c823 Gerhaus (nom) irminon-vol2 9, Ved, Girhaus (nom) ibid. 4, CE
Germany
Early New High German
1497 Gerhaus Nurn1497 2140, Gerhaws ibid. 1317
Cite as: S.L. Uckelman. "Gerhaus". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2019, no. 1. http://dmnes.org/2019/1/name/Gerhaus.