Acacia: A plant genus of the family FABACEAE. The gums and tanning agents obtained from Acacia are called GUM ARABIC. The common name of catechu is more often used for Areca catechu (ARECA).Gum Arabic: Powdered exudate from various Acacia species, especially A. senegal (Leguminosae). It forms mucilage or syrup in water. Gum arabic is used as a suspending agent, excipient, and emulsifier in foods and pharmaceuticals.