Dictionary of Medieval Names
from European Sources

Guither m. Old Saxon widu, wido, Old High German witu 'wood' + Old English here, Old High German heri 'host, army'.

France
Latin
1147 Guitherius (nom) clairvaux-12thc 19, Guitterius (nom) ibid. 19
Cite as: S.L. Uckelman. "Guither". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2017, no. 1. http://dmnes.org/2017/1/name/Guither.