This name may have several significations, according to the language in which it was first given. Dorr, Gaelic, difficult, easily vexed. Dur, Gaelic, persevering, earnest, obstinate. Dorr, Icelandic, a spear. Dor, Cor. British, the earth; also dorre, to break. Doir, local, a woody place. Dar, Welsh, oak.

Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.