ammoniac(redirected from Ammoniacum)
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A gum resin from a plant of western Asia, Dorema ammoniacum (family Umbelliferae); used internally as a stimulant and expectorant, and externally as a counterirritant plaster.
A strong-smelling gum resin from the stems of a plant (Dorema ammoniacum) of western Asia, formerly used in perfumery and in medicine as an expectorant and a stimulant. Also called gum ammoniac.