2. The elastic fibrous skeleton of many species of horny
Spongi[ae] (keratosa), used for many purposes, especially
the varieties of the genus {Spongia}. The most valuable
sponges are found in the Mediterranean and the Red Sea,
and on the coasts of Florida and the West Indies.
3. Fig.: One who lives upon others; a pertinaceous and
indolent dependent; a parasite; a sponger.
4. Any spongelike substance. Specifically:
(a) Dough before it is kneaded and formed into loaves, and
after it is converted into a light, spongy mass by the
agency of the yeast or leaven.
(b) Iron from the puddling furnace, in a pasty condition.
(c) Iron ore, in masses, reduced but not melted or worked.
5. (Gun.) A mop for cleaning the bore of a cannon after a
discharge. It consists of a cylinder of wood, covered with
sheepskin with the wool on, or cloth with a heavy looped
nap, and having a handle, or staff.
6. (Far.) The extremity, or point, of a horseshoe, answering
to the heel.
{Bath sponge}, any one of several varieties of coarse
commercial sponges, especially {Spongia equina}.
{Cup sponge}, a toilet sponge growing in a cup-shaped form.
{Glass sponge}. See {Glass-sponge}, in the Vocabulary.
{Glove sponge}, a variety of commercial sponge ({Spongia
officinalis}, variety {tubulufera}), having very fine
fibers, native of Florida, and the West Indies.
{Grass sponge}, any one of several varieties of coarse
commercial sponges having the surface irregularly tufted,
as {Spongia graminea}, and {S. equina}, variety
{cerebriformis}, of Florida and the West Indies.
{Horse sponge}, a coarse commercial sponge, especially
{Spongia equina}.
{Platinum sponge}. (Chem.) See under {Platinum}.
{Pyrotechnical sponge}, a substance made of mushrooms or
fungi, which are boiled in water, dried, and beaten, then
put in a strong lye prepared with saltpeter, and again
dried in an oven. This makes the black match, or tinder,
brought from Germany.
{Sheep's-wool sponge}, a fine and durable commercial sponge
({Spongia equina}, variety {gossypina}) found in Florida
and the West Indies. The surface is covered with larger
and smaller tufts, having the oscula between them.
{Sponge cake}, a kind of sweet cake which is light and
spongy.
{Sponge lead}, or {Spongy lead} (Chem.), metallic lead
brought to a spongy form by reduction of lead salts, or by
compressing finely divided lead; -- used in secondary
batteries and otherwise.
{Sponge tree} (Bot.), a tropical leguminous tree ({Acacia
Farnesiana}), with deliciously fragrant flowers, which are
used in perfumery.
{Toilet sponge}, a very fine and superior variety of
Mediterranean sponge ({Spongia officinalis}, variety
{Mediterranea}); -- called also {turkish sponge}.
{To set a sponge} (Cookery), to leaven a small mass of flour,
to be used in leavening a larger quantity.
{To throw up the sponge}, to give up a contest; to
acknowledge defeat; -- from a custom of the prize ring,
the person employed to sponge a pugilist between rounds
throwing his sponge in the air in token of defeat. [Cant
or Slang] ``He was too brave a man to throw up the sponge
to fate.'' --Lowell.