zinc-amidehttp://www.oed.com/dictionary/zinc-amide_n%3Ftab%3Dmeaning_and_usezinc-amide, n.
First published 1921; not fully revised

zinc-amidenoun

  1. 1859–
    (See quots.).
    1. 1859
      Action of Zinc-ethyl on Ammonia..after a little while, zinc-amide NH2Zn separates out.
      H. Watts, translation of L. Gmelin, Hand-book of Chemistry vol. XIII. 503

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

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