In full "gum adragant", "adragant gum". A plant gum obtained from various shrubs of the genus Astralagus.
((n.) Gum tragacanth.)
Origin:
Late 17th century. From French adragant, variant or alteration of dragant, probably by association with Middle French diadragum, diadragentum, etc., a medicinal preparation containing tragacanth.