Jörd, in Norse mythology, a giantess, mother of the deity Thor and mistress of the god Odin. In the late pre-Christian era she was believed to have had a husband of the same name, perhaps indicating her transformation into a masculine personality. Her name is connected with that of the Lithuanian thunder god Perkun; both are thought to be related to Old High German forha, “oak” (also “fir”), and Latin quercus, “oak.”