What does "ammoniacal" mean?

Ammoniacal: 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 Etym: [L. sal ammoniacus], the salt usually called chloride of ammonium, and formerly muriate of ammonia.