Aqua regia
WordNet
noun
(1) A yellow fuming corrosive mixture of nitric and hydrochloric acid that dissolves metals (including gold)
WiktionaryText
Etymology
aqua regia, royal water, so named because it is one of the few solvents capable of dissolving noble metals.
Noun
(abbreviation A.R.)
- An extremely powerful acid mixture composed of three parts concentrated hydrochloric acid to one part concentrated nitric acid.