-ˈrēj(ē)ə noun
( plural aquae regi·ae -jēˌē)
Etymology: New Latin, literally, royal water; from its ability to dissolve gold
: a very corrosive fuming yellow liquid made by mixing nitric and hydrochloric acids usually in the proportion of one volume of nitric to three or four of hydrochloric and used in dissolving metals (as gold or platinum) and in etching — called also nitrohydrochloric acid