【医】 紫胶, 虫胶

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.