An Etymological Dictionary of the German Language/Geschirr
Geschirr, n., ‘gear, trappings, implements, ware,’ from MidHG. geschirre, OHG. giscirri, n., ‘dishes, vessel, instrument, utensils.’ The more general meaning, ‘instrument of every kind,’ is also seen, especially in anschirren (ModHG. simply), ‘to harness a horse.’ The origin of the stem, which does not appear elsewhere in Teut., is obscure.