The Collaborative International Dictionary of English v.0.48:

Sponge \Sponge\ (sp[u^]nj), n. [OF. esponge, F. ['e]ponge, L.
   spongia, Gr. spoggia`, spo`ggos. Cf. Fungus, Spunk.]
   [Formerly written also spunge.]
   1. (Zool.) Any one of numerous species of Spongiae, or
      Porifera. See Illust. and Note under Spongiae.
      [1913 Webster]

   2. The elastic fibrous skeleton of many species of horny
      Spongiae (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.
      [1913 Webster]

   3. Fig.: One who lives upon others; a pertinacious and
      indolent dependent; a parasite; a sponger.
      [1913 Webster]

   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.
          [1913 Webster]

   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.
      [1913 Webster]

   6. (Far.) The extremity, or point, of a horseshoe, answering
      to the heel.
      [1913 Webster]

   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 tubulifera), 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 Spongia 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; -- now,
      throw in the towel is more common, and has the same
      origin and meaning. [Cant or Slang] "He was too brave a
      man to throw up the sponge to fate." --Lowell.

   Vegetable sponge. (Bot.) See Loof.

   Velvet sponge, a fine, soft commercial sponge (Spongia
      equina, variety meandriniformis) found in Florida and the
      West Indies.

   Vitreous sponge. See Glass-sponge.

   Yellow sponge, a common and valuable commercial sponge
      (Spongia agaricina, variety corlosia) found in Florida
      and the West Indies.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sponge \Sponge\, v. t. [imp. & p. p. Sponged (sp[u^]njd); p.
   pr. & vb. n. Sponging (sp[u^]n"j[i^]ng).]
   1. To cleanse or wipe with a sponge; as, to sponge a slate or
      a cannon; to wet with a sponge; as, to sponge cloth.
      [1913 Webster]

   2. To wipe out with a sponge, as letters or writing; to
      efface; to destroy all trace of. --Hooker.
      [1913 Webster]

   3. Fig.: To deprive of something by imposition. "How came
      such multitudes of our nation . . . to be sponged of their
      plate and their money?" --South.
      [1913 Webster]

   4. Fig.: To get by imposition or mean arts without cost; as,
      to sponge a breakfast. --Swift.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sponge \Sponge\, v. i.
   1. To suck in, or imbibe, as a sponge.
      [1913 Webster]

   2. Fig.: To gain by mean arts, by intrusion, or hanging on;
      as, an idler sponges on his neighbor. --E. Eggleston.
      [1913 Webster]

            The fly is an intruder, and a common smell-feast,
            that sponges upon other people's trenchers.
                                                  --L'Estrange.
      [1913 Webster]

   3. To be converted, as dough, into a light, spongy mass by
      the agency of yeast, or leaven.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sponge
    n 1: a porous mass of interlacing fibers that forms the internal
         skeleton of various marine animals and usable to absorb
         water or any porous rubber or cellulose product similarly
         used
    2: someone able to acquire new knowledge and skills rapidly and
       easily; "she soaks up foreign languages like a sponge" [syn:
       quick study, sponge]
    3: a follower who hangs around a host (without benefit to the
       host) in hope of gain or advantage [syn: leech, parasite,
       sponge, sponger]
    4: primitive multicellular marine animal whose porous body is
       supported by a fibrous skeletal framework; usually occurs in
       sessile colonies [syn: sponge, poriferan, parazoan]
    v 1: wipe with a sponge, so as to clean or moisten
    2: ask for and get free; be a parasite [syn: mooch, bum,
       cadge, grub, sponge]
    3: erase with a sponge; as of words on a blackboard
    4: soak up with a sponge
    5: gather sponges, in the ocean

Moby Thesaurus II by Grady Ward, 1.0:

370 Moby Thesaurus words for "sponge":
   Ace bandage, Band-Aid, Finnish bath, India rubber, Japanese bath,
   Loch Ness monster, Russian bath, Swedish bath, Turkish bath,
   ablution, absorb, absorbency, absorbent, absorption, adhesive tape,
   adsorb, adsorbent, adsorption, air, air-dry, alevin, anhydrate,
   application, asperge, assimilate, assimilation, bake, band,
   bandage, bandaging, baptize, barnacle, bath, bathe, batten on,
   beat, bedew, benthon, benthos, bespatter, besprinkle, bibber,
   binder, bloodsucker, blot, blot out, blot up, blotter, blotting,
   blotting paper, boozehound, boozer, bottle sucker, brace, brush,
   bubble, bum, burn, butter, cancel, cast, cataplasm, cetacean,
   chaff, chemisorb, chemisorption, chemosorb, chemosorption, chip,
   cleaning out, cobweb, colander, cold shower, compress, cork,
   cotton, court plaster, cravat, cribble, cribriformity, cribrosity,
   cross out, crush, cure, dabble, damp, dampen, dash, deadbeat,
   dehumidify, dehydrate, dele, delete, dental pulp, desiccate, dew,
   digest, digestion, dolphin, douche, douching, down, drain,
   dressing, drink, drink in, drink up, drunk, dry, dust, efface,
   elastic bandage, elbow bender, elution, elutriation, endosmosis,
   enema, engross, engrossment, epithem, eradicator, erase, eraser,
   ether, evaporate, exosmosis, expunge, expunger, exsiccate, fairy,
   fatten on, feather, feed on, filter in, fingerling, fire, fish,
   flue, fluff, flush, flush out, flushing, flushing out, foam,
   four-tailed bandage, freeload, freeloader, froth, fry, fuzz,
   game fish, gargle, gauze, ginhound, give, gossamer, grilse,
   guzzler, hanger-on, hip bath, holystone, honeycomb, hooch hound,
   hose, hose down, humect, humectate, humidify, hummum, imbibe,
   inebriate, infiltrate, infiltration, insolate, irrigate,
   irrigation, kiln, kipper, lather, lathering, launder, lavabo,
   lavage, lavation, lave, laving, leech, lint, live off of,
   lounge lizard, lush, lusher, man-eater, man-eating shark,
   marine animal, mash, minnow, minny, moisten, mop, mop up, mopping,
   mopping up, mote, mummify, mush, needle bath, nekton, net,
   obliterate, osmose, osmosis, paddle, panfish, paper pulp, parasite,
   parch, paste, percolate in, percolation, pith, plankton, plaster,
   plaster cast, pledget, plunge bath, porosity, porousness, porpoise,
   porridge, poultice, present, pudding, pulp, pulp lead, pulpwood,
   rag pulp, raze, riddle, rinse, rinse out, rinsing,
   ritually immerse, roller, roller bandage, rub, rub out, rubber,
   rubber bandage, rule out, rum hound, rummy, salmon, sauce, sauna,
   sauna bath, scorch, scour, scouring, scratch, scratch out, screen,
   scrub, scrub up, scrubbing, scrubbing up, sea monster, sea pig,
   sea serpent, sea snake, sear, seep in, seepage, shampoo, shark,
   shower, shower bath, shrivel, sieve, sievelikeness, sitz bath,
   sling, slobber, slop, slosh, sluice, sluice out, slurp up, smash,
   smell-feast, smoke, smolt, soak, soak in, soak up, soap, soaping,
   sorb, sorption, sot, souse, sparge, spatter, spiv, splash,
   splatter, splint, sponge bath, sponge on, sponge out, sponger,
   sponging, spray, sprinkle, spume, squash, stew, strainer, straw,
   strike out, stupe, sucker, sulfate pulp, sulfite pulp, sun,
   sun-dry, swab, swabbing, swash, sweat bath, swill up, swillbelly,
   swillbowl, swillpot, syringe, take in, take up, tampon, tape, tent,
   thistledown, tippler, toivel, torrefy, tourniquet, towel,
   triangular bandage, tropical fish, tub, wash, wash out, wash up,
   washing, washing up, washout, washup, water, weazen, wet, wet down,
   whale, whirlpool bath, white lead, wino, wipe, wipe out, wiping up,
   wither, wizen, wood pulp



The Jargon File (version 4.4.7, 29 Dec 2003):

sponge
 n.

    [Unix] A special case of a filter that reads its entire input before
    writing any output; the canonical example is a sort utility. Unlike most
    filters, a sponge can conveniently overwrite the input file with the output
    data stream. If a file system has versioning (as ITS did and VMS does now)
    the sponge/filter distinction loses its usefulness, because directing
    filter output would just write a new version. See also slurp.


The Free On-line Dictionary of Computing (30 December 2018):

sponge

    A kind of Unix filter that reads its entire input
   before writing any output, e.g. sort.  Unlike most filters, a
   sponge can safely overwrite the input file with the output data.

   On a file system with file versioning (like ITS or VMS) the
   distinction is less significant because output would be written to
   a new version of the input file anyway.

   See also slurp.

   [Jargon File]

   (2014-06-21)


Easton's 1897 Bible Dictionary:

Sponge
   occurs only in the narrative of the crucifixion (Matt. 27:48;
   Mark 15:36; John 19:29). It is ranked as a zoophyte. It is found
   attached to rocks at the bottom of the sea.