Source : Webster's Revised Unabridged Dictionary (1913)

Ammoniac \Am*mo"ni*ac\, Ammoniacal \Am`mo*ni"a*cal\, a.
   Of or pertaining to ammonia, or possessing its properties;
   as, an ammoniac salt; ammoniacal gas.

   {Ammoniacal engine}, an engine in which the vapor of ammonia
      is used as the motive force.

   {Sal ammoniac} [L. sal ammoniacus], the salt usually called
      {chloride of ammonium}, and formerly {muriate of ammonia}.

Source : WordNet®

ammoniacal
     adj : pertaining to or containing or similar to ammonia [syn: {ammoniac}]