ornamental stone, 1590s, from Fr. le jade, error for earlier l'ejade, from Sp. piedra de (la) ijada (1569), "stone of colic, pain in the side" (jade was thought to cure this), from V.L. *iliata, from L. ilia (pl.) "flanks, kidney area."
"worn-out horse," late 14c., possibly from O.N. jalda "mare," from Finno-Ugric (cf. Mordvin al'd'a "mare"). As a term of abuse for a woman, it dates from 1560.
1700, "one that is half Whore, half Bawd" ["Dictionary of the Canting Crew"]; "a decayed strumpet" [Johnson], from Fr. haridelle "a poore tit, or leane ill-favored jade," [Cotgrave, 1611], in Fr. from 16c., of unknown origin.