Meaning of fuming nitric acid

fum'ing ni'tric ac'id

Pronunciation: [key]
  1. a colorless, yellowish, or brownish fuming corrosive liquid, usually prepared from nitric acid by the addition of excess nitrogen dioxide: used in organic synthesis for nitration, and as an oxidizer in liquid propellants for rockets.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.