zone-levelledhttp://www.oed.com/dictionary/zone-levelled_adj%3Ftab%3Dmeaning_and_usezone-levelled, adj.
First published 1986; not fully revised

zone-levelledadjective

  1. 1956–
    1. 1956
      p fluctuations in zone leveled material are generally coarse.
      Bell System Technical Journal vol. 35 657

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

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