nitric oxide: Meaning and Definition of

ni'tric ox'ide

Pronunciation: [key]
— Chem. Chem.
  1. a colorless, slightly water-soluble gas, NO, formed by the action of dilute nitric acid on copper, and by the direct combination of atmospheric oxygen and nitrogen at the high temperatures of an electric arc: an intermediate in the manufacture of nitric acid.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.