"to make a harsh, grating sound," 1526, usually said to be echoic or imitative, but no one explains how, or of what. Fig. sense of "have an unpleasant effect on" is from 1538.
jar
"cylindrical vessel," 1421, possibly from M.Fr. jarre "liquid measure" (smaller than a barrel), from Prov. jarra, from Arabic jarrah "earthen water vessel" (whence also Sp. jarra, It. giarra).