Source : Webster's Revised Unabridged Dictionary (1913)

Muriatic \Mu`ri*at"ic\, a. [L. muriaticus pickled, from muria
   brine: cf. F. muriatique.] (Chem.)
   Of, pertaining to, or obtained from, sea salt, or from
   chlorine, one of the constituents of sea salt; hydrochloric.

   {Muriatic acid}, hydrochloric acid, {HCl}; -- formerly called
      also {marine acid}, and {spirit of salt}. See
      {hydrochloric}, and the Note under {Muriate}.

Source : WordNet®

muriatic acid
     n : a former name for hydrochloric acid