n. An aggregation of bubbles formed on the surface of water or other liquid by violent agitation or by fermentation; froth; spume: as, the foam of breaking waves; the foam of the mouth.n. The foaming sea; a foaming wave.n. Figuratively, foaming rage; fury.n. In mineralogy, same as aphrite.n. Scum, as from molten metal.To form or gather foam, as water (the crest of a wave), etc., from agitation, a liquor from fermentation, or the mouth from rage or disease; froth; spume.To become filled or covered with foam, as a steam-boiler when the water is frothy.To cause to foam; fill with something that foams; make frothy: as, to foam a tankard.To throw out with rage or violence: usually with out.