What is "gum acacia"

Gum \Gum\, n. [OE. gomme, gumme, F. gomme, L. gummi and commis, fr. Gr. ?, prob. from an Egyptian form kam?; cf. It. gomma.]

1. A vegetable secretion of many trees or plants that hardens when it exudes, but is soluble in water; as, gum arabic; gum tragacanth; the gum of the cherry tree. Also, with less propriety, exudations that are not soluble in water; as, gum copal and gum sandarac, which are really resins.

2. (Bot.) See Gum tree, below.

3. A hive made of a section of a hollow gum tree; hence, any roughly made hive; also, a vessel or bin made of a hollow log. [Southern U. S.]

4. A rubber overshoe. [Local, U. S.]

   Black gum, Blue gum, British gum, etc. See under Black, Blue, etc.

   Gum Acaroidea, the resinous gum of the Australian grass tree ( Xanlhorrh[oe]a).

   Gum animal (Zo["o]l.), the galago of West Africa; -- so called because it feeds on gums. See Galago.

   Gum animi or anim['e]. See Anim['e].

   Gum arabic, a gum yielded mostly by several species of Acacia (chiefly A. vera and A. Arabica) growing in Africa and Southern Asia; -- called also gum acacia. East Indian gum arabic comes from a tree of the Orange family which bears the elephant apple.

   Gum butea, a gum yielded by the Indian plants Butea frondosa and B. superba, and used locally in tanning and in precipitating indigo.

   Gum cistus, a plant of the genus Cistus ( Cistus ladaniferus), a species of rock rose.

   Gum dragon. See Tragacanth.

   Gum elastic, Elastic gum. See Caoutchouc.

   Gum elemi. See Elemi.

   Gum juniper. See Sandarac.

   Gum kino. See under Kino.

   Gum lac. See Lac.

   Gum Ladanum, a fragrant gum yielded by several Oriental species of Cistus or rock rose.

   Gum passages, sap receptacles extending through the parenchyma of certain plants ( Amygdalace[ae], Cactace[ae], etc.), and affording passage for gum.

   Gum pot, a varnish maker's utensil for melting gum and mixing other ingredients.

   Gum resin, the milky juice of a plant solidified by exposure to air; one of certain inspissated saps, mixtures of, or having properties of, gum and resin; a resin containing more or less mucilaginous and gummy matter.

   Gum sandarac. See Sandarac.

   Gum Senegal, a gum similar to gum arabic, yielded by trees ( Acacia Verek and A. Adansoni["a]) growing in the Senegal country, West Africa.

   Gum tragacanth. See Tragacanth.

   Gum water, a solution of gum, esp. of gum arabic, in water.

   Gum wood, the wood of any gum tree, esp. the wood of the Eucalyptus piperita, of New South Wales.

Acacia \A*ca"cia\, n.; pl. E. Acacias, L. Acaci[ae]. [L. from Gr. ?; orig. the name of a thorny tree found in Egypt; prob. fr. the root ak to be sharp. See Acute.]

1. A genus of leguminous trees and shrubs. Nearly 300 species are Australian or Polynesian, and have terete or vertically compressed leaf stalks, instead of the bipinnate leaves of the much fewer species of America, Africa, etc. Very few are found in temperate climates.

2. (Med.) The inspissated juice of several species of acacia; -- called also gum acacia, and gum arabic.

n. gum arabic

n. gum from an acacia tree; used as a thickener (especially in candies and pharmaceuticals) [syn: gum arabic]