zwitterionichttp://www.oed.com/dictionary/zwitterionic_adj%3Ftab%3Dmeaning_and_usezwitterionic, adj.
First published 1986; not fully revised

zwitterionicadjective

Chemistry.
  1. 1946–
    Stressed as ˌzwitteriˈonic.
    1. 1946
      A hybrid structure derived from a number of ionic states of which there are..eight zwitterionic forms.
      Nature 16 November 703/1
    2. 1949
      These [substances]..may be neutral, acidic, basic, or zwitterionic.
      E. P. Abraham & N. G. Heatley in H. W. Florey et al., Antibiotics vol. I. ii. 94
    3. 1981
      Vesicles of zwitterionic phosphatidylcholine.
      Biochimica et Biophysica Acta vol. 668 117

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

zwitterion, n. was first published in 1986; not fully revised.