Definition of aqua regia in English:

aqua regia

Pronunciation /ˌäkwə ˈrēj(ē)ə/ /ˌɑkwə ˈridʒ(i)ə/ /ˌakwə ˈrēj(ē)ə/ /ˌækwə ˈridʒ(i)ə/


  • A mixture of concentrated nitric and hydrochloric acids. It is a highly corrosive liquid that will dissolve gold and other resistant substances.

    ‘It is not attacked by most acids, although it does dissolve in aqua regia (a mixture of concentrated nitric acid and 3-4 parts of hydrochloric acid).’
    • ‘Some time before 1300, sulfuric acid was prepared, and alchemists created aqua regia, a mixture of sulfuric and nitric acids that is capable of dissolving gold, platinum, and many other materials.’
    • ‘Gold resists corrosion by air and most chemicals but can be dissolved in a mixture of nitric and hydrochloric acids, a solution called aqua regia because it dissolves the ‘king of metals’.’
    • ‘Gold also resists attack by most acids but is soluble in aqua regia, a mixture of three parts hydrochloric acid and one part nitric acid.’
    • ‘His method had two key innovations: he used aqua regia with the most effective molar ratio of hydrochloric to nitric acids; and the amount of aqua regia used was sufficient to dissolve only about half of the crude ore.’


Early 17th century Latin, literally ‘royal water’.