speiss (spīs) n. An arsenic compound or a mixture of arsenic compounds resulting from the smelting of iron, cobalt, nickel, and copper ores.
[German Speise, food, speiss, from Middle High German spīse, food, from Old High German spīsa, probably from Medieval Latin spēnsa, storehouse, or spēsa, provisions, both from Latin expēnsa (pecūnia), (money) paid out; see expense.]