A mass of small bubbles formed in or on a liquid.

synonym: foam.

Roget 653: uncleanness etc. adj.; impurity; immundity^†, immundicity^†; impurity etc. 961 [of mind]. defilement, contamination etc. v.; defoedation^†; soilure^†, soiliness^†; abomination; leaven; taint, tainture^†; fetor etc. 401^†.    decay; putrescence, putrefaction; corruption; mold, must, mildew, dry rot, mucor, rubigo^†.    slovenry^†; slovenliness etc. adj.; squalor.    dowdy, drab, slut, malkin^†, slattern, sloven, slammerkin^†, slammock^†, slummock^†, scrub, draggle-tail, mudlark^†, dust-man, sweep; beast.    dirt, filth, soil, slop; dust, cobweb, flue; smoke, soot, smudge, smut, grit, grime, raff^†; sossle^†, sozzle^†.    sordes^†, dregs, grounds, lees; argol^†; sediment, settlement heeltap^†; dross, drossiness^†; mother^†, precipitate, scoriae, ashes, cinders.    recrement^†, slag; scum, froth.    hogwash; ditchwater^†, dishwater, bilgewater^†; rinsings, cheeseparings; sweepings etc. (useless refuse) 645; offscourings^†, outscourings^†; off scum; caput mortuum [Lat.], residuum, sprue, fecula [Lat.], clinker, draff^†; scurf, scurfiness^†; exuviae [Lat.], morphea; fur, furfur^†; dandruff, tartar.    riffraff; vermin, louse, flea, bug, chinch^†.    mud, mire, quagmire, alluvium, silt, sludge, slime, slush, slosh, sposh [U.S.].    spawn, offal, gurry [U.S.]; lientery^†; garbage, carrion; excreta etc. 299; slough, peccant humor, pus, matter, suppuration, lienteria^†; faeces, feces, excrement, ordure, dung, crap [Vulg.], shit [Vulg.]; sewage, sewerage; muck; coprolite; guano, manure, compost.    dunghill, colluvies^†, mixen^†, midden, bog, laystall^†, sink, privy, jakes; toilet, john, head; cess^†, cesspool; sump, sough, cloaca, latrines, drain, sewer, common sewer; Cloacina; dust hole.    sty, pigsty, lair, den, Augean stable^†, sink of corruption; slum, rookery.    ... show more

Roget 353: bubble, foam, froth, head, spume, lather, suds, spray, surf, yeast, barm^†, spindrift.    cloud, vapor, fog, mist, haze, steam, geyser; scud, messenger, rack, nimbus; cumulus, woolpack^†, cirrus, stratus; cirrostratus, cumulostratus; cirrocumulus; mackerel sky, mare's tale, dirty sky; curl cloud; frost smoke; thunderhead.    [Science of clouds] nephelognosy^†; nephograph^†, nephology^†.    effervescence, fermentation; bubbling etc. v.. nebula; cloudliness etc. (opacity) 426^†; nebulosity etc. (dimness) 422.    ... show more

Dutch: schuim
Polish: piana, pianka

Become bubbly or frothy or foaming:
— The boiling soup was frothing.

synonyms: effervesce, fizz, foam, form bubbles, sparkle.

Roget 353: bubble, boil, foam, froth, mantle, sparkle, guggle^†, gurgle; effervesce, ferment, fizzle.   

Dutch: bruisen, schuimen

Make froth or foam and become bubbly.

synonyms: spume, suds.

Exude or expel foam.