Ither m. Uncertain element + Old English here, Old High German heri 'host, army'. Morlet I:143a says the origin of the prototheme is obscure, but may be related to idh 'work' or idhja 'negotiate'.

Belgium

Middle Dutch

● 1377 Ydier (nom) RSG1376-89 p. 77, Ydiere (dat) ibid. p. 78

France

Latin

● c823 Itharius (nom) irminon-vol2 5, Palatiolum; 1135 Yterius (nom) clairvaux-12thc 7, Ytherus (nom) ibid. 7; 1138x1162 Iterius (nom) ibid. 56; 1147 Iterii (gen) ibid. 17, Iterio (abl) ibid. 17, Iterius (nom) ibid. 14; c1150 Yterius (nom) CartSavII 200; 1163 Iterio (abl) clairvaux-12thc 99; 1163–64 Iterius (nom) ibid. 106; 1164 Iterius (nom) ibid. 120; 1179 Iterius (nom) ibid. 177, Iterus (nom) ibid. 178, Yterii (gen) ibid. 176, Yterus (nom) ibid. 176

Middle French

● 1418 Ydier HGParis p. 384