1. (n.) The white substance, consisting of an aggregation of bubbles, which is formed on the surface of liquids, or in the mouth of an animal, by violent agitation or fermentation; froth; spume; scum; as, the foam of the sea.

2. (n.) To gather foam; to froth; as, the billows foam.

3. (n.) To form foam, or become filled with foam; -- said of a steam boiler when the water is unduly agitated and frothy, as because of chemical action.

4. (v.t.) To cause to foam; as, to foam the goblet; also (with out), to throw out with rage or violence, as foam.

Foamite acid aerate air alabaster automatic sprinkler beat blubber boil breakers breeze bubble bubbles butter carbon tet carbon tetrachloride carbon-dioxide foam carbonation chaff chalk chip churn clay cobweb collar cork cream cushion deck gun deluge set dough down dribble drivel driven snow drool dust effervescence eiderdown ether expectoration extinguisher fairy feather feather bed feathers ferment fire apparatus fire engine fire hose fire hydrant fireplug fizz fleece floss flour flue fluff foam extinguisher froth fume fuzz gossamer head hook-and-ladder ivory kapok ladder pipe lather lily maggot mantle meringue milk mote mousse mouth-watering offscum paper pearl pillow plash plush ptyalism pudding puff pumper putty rubber saliva salivation satin scud scum sea foam seethe sheet shower sialagogue silk silver simmer slabber slaver slobber slosh snorkel snow soapsuds soda souffle sparge sparkle spatter spindrift spit spittle splash splatter sponge spoondrift spray sprinkle sprinkler sprinkler head sprinkler system spume sputum stew stinging stir straw sud suds super-pumper surf swan swansdown swash thistledown velvet water water cannon wax wet blanket whip whisk white water wool yeast zephyr