*nitrohydrochloric*

a. [ Nitro- + hydrochloric. ] (Chem.) Of, pertaining to, or containing, nitric and hydrochloric acids. [ 1913 Webster ]

Nitrohydrochloric acid, a mixture of nitric and hydrochloric acids, usually in the proportion of one part of the former to three of the latter, and remarkable for its solvent action on gold and platinum; -- called also aqua regia, and nitromuriatic acid. [ 1913 Webster ]