zinc-oxidehttp://www.oed.com/dictionary/zinc-oxide_n%3Ftab%3Dmeaning_and_usezinc oxide, n.
First published 1921; not fully revised

zinc oxidenoun

  1. 1849–
    1. 1849
      Small quantities of iron and zinc oxides.
      D. Campbell, Practical Text-book of Inorganic Chemistry 223

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

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