gum arabic (gum acacia) Exudate from the stems of Acacia spp.; the best product comes from A. senegal. Used as thickening agent, as stabilizer, often in combination with other gums, in gum drops and soft jelly gums, and to prevent crystallization in sugar confectionery. Also used as the adhesive on postage stamps.

gum ar·a·bic • n. a gum exuded by some kinds of acacia and used as an emulsifier, in glue, as the binder for watercolor paints, and in incense.