a strong, highly corrosive acid that is a water solution of the gas hydrogen chloride, HCl: it is widely used in ore processing, for cleaning metals, as a reagent, etc.
See hydrochloric acid in American Heritage Dictionary 4
(hīˌdrə-klôrˈĭk, -klōrˈ-)
noun
A clear, colorless, fuming, poisonous, highly acidic aqueous solution of hydrogen chloride, HCl, used as a chemical intermediate and in petroleum production, ore reduction, food processing, pickling, and metal cleaning. It is found in the stomach in dilute form.