zinc-ironhttp://www.oed.com/dictionary/zinc-iron_n%3Ftab%3Dmeaning_and_usezinc-iron, n. & adj.
First published 1921; not fully revised

zinc-ironnoun & adjective

  1. 1849–
    a. n. An alloy of zinc and iron; b. adj. consisting of zinc and iron.
    1. 1849
      The zinc-iron circuit.
      H. M. Noad, Lectures Electr. (ed. 3) 177
    2. 1868
      Kreittonnite, or Zinc-Iron Gahnite.
      J. D. Dana, System of Mineralogy (ed. 5) 149

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

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