GUM, n. The hard fleshy substance of the jaws which invests the teeth.

GUM, n. [L. gummi.] The mucilage of vegetables; a concrete juice which exudes through the bark of trees, and thickens on the surface. It is soluble in water, to which it gives a viscous and adhesive quality. It is insoluble in alcohol, and coagulates in weak acids. When dry, it is transparent and brittle, not easily pulverized, and of an insipid or slightly saccharine taste. Gum differs from resin in several particulars, but custom has inaccurately given the name of gum to several resins and gum-resins, as gum-copal. gum-sandarach, gum-ammoniac, and others. The true gums are gumarabic, gum-senegal, gum-tragacanth,and the gums of the peach, plum and cherry trees, &c.

Gum-elastic, or Elastic-gum, [caoutchouc,] is a singular substance, obtained from a tree in America by incision. It is a white juice, which, when dry, becomes very tough and elastic, and is used for bottles,surgical instruments, &c.

GUM, v.t. To smear with gum.

A tree; the Nyssa multiflora, called also black gum and sour gum.

The hard fleshy substance of the jaws which invests the teeth.

The concrete mucilage of vegetables; a concrete juice which exsudes through the bark of trees, and thickens on the surface. It is soluble in water, to which it gives a viscous and adhesive quality. It is insoluble in alcohol, and coagulates in weak acids. When dry, it is transparent and brittle, not easily pulverized, and of an insipid or slightly saccharine taste. Gum differs from resin to several particulars, but custom has inaccurately given the name of gum to several resins and gum-resins, as gum-copal, gum-sandarach, gum-ammoniac, and others. The true gums are gum-arabic, gum-senegal, gum-tragacanth, and the gums of the peach, plum and cherry trees, &c. Nicholson. Hooper.

1. To smear with gum.
2. To unite by a viscous substance.

1. The dense tissues which invest the teeth, and cover the adjacent parts of the jaws.
   
   

   Gum rash (Med.), strophulus in a teething child; red gum. -- Gum stick, a smooth hard substance for children to bite upon while teething.

2. To deepen and enlarge the spaces between the teeth of (a worn saw). See Gummer.
3. 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.
4. To smear with gum] to close with gum; to unite or stiffen by gum or a gumlike substance; to make sticky with a gumlike substance.
   
   

   He frets like a gummed velvet. Shak.

5. To exude or from gum; to become gummy.
6. See Gum tree, below.
7. 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.]
8. 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 (Xanlhorrhœa). -- Gum animal (Zoöl.), the galago of West Africa; -- so called because it feeds on gums. See Galago. -- Gum animi or animé. See Animé. - - 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 (Amygdalaceæ, Cactaceæ, 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. Adansoniä) growing in the Senegal country, West Africa. -- Gum tragacanth. See Tragacanth. -- Gum tree, the name given to several trees in America and Australia: (a) The black gum (Nyssa multiflora), one of the largest trees of the Southern States, bearing a small blue fruit, the favorite food of the opossum. Most of the large trees become hollow. (b) A tree of the genus Eucalyptus. See Eucalpytus. (c) The sweet gum tree of the United States (Liquidambar styraciflua), a large and beautiful tree with pointedly lobed leaves and woody burlike fruit. It exudes an aromatic terebinthine juice. -- 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.