zinc-powderhttp://www.oed.com/dictionary/zinc-powder_n%3Ftab%3Dmeaning_and_usezinc-powder, n.
First published 1921; not fully revised

zinc-powdernoun

  1. 1881–
    1. 1881
      Two grams of the zinc powder are weighed out.
      Journal of Chemical Society vol. 39 462

Originally published as part of the entry for zinc, n.

zinc, n. was first published in 1921; not fully revised.