The Collaborative International Dictionary of English v.0.48:

Nitrohydrochloric \Ni`tro*hy`dro*chlo"ric\, 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]

The Collaborative International Dictionary of English v.0.48:

Aqua \A"qua\, n. [L. See Ewer.]
   Water; -- a word much used in pharmacy and the old chemistry,
   in various signification, determined by the word or words
   annexed.
   [1913 Webster]

   Aqua ammoni[ae], the aqueous solution of ammonia; liquid
      ammonia; often called aqua ammonia.

   Aqua marine, or Aqua marina. Same as Aquamarine.

   Aqua regia. [L., royal water] (Chem.), a very corrosive
      fuming yellow liquid consisting of nitric and hydrochloric
      acids. It has the power of dissolving gold, the "royal"
      metal.

   Aqua Tofana, a fluid containing arsenic, and used for
      secret poisoning, made by an Italian woman named Tofana,
      in the middle of the 17th century, who is said to have
      poisoned more than 600 persons. --Francis.

   Aqua vit[ae][L., water of life. Cf. Eau de vie,
      Usquebaugh], a name given to brandy and some other
      ardent spirits. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

aqua regia
    n 1: a yellow fuming corrosive mixture of nitric and
         hydrochloric acid that dissolves metals (including gold)
         [syn: aqua regia, nitrohydrochloric acid]