foam

foam n Foam, froth, spume, scum, lather, suds, yeast are comparable when they denote either a mass of bubbles gathering in or on the surface of a liquid or something as insubstantial as such a mass.

Foam is the most comprehensive of these terms but is not interchangeable with all; it implies an aggregation of small bubbles such as rises to the top of a fermenting liquor or an effervescing or boiling liquid, or appears on the surface of the sea when agitated by high winds or covered with breaking waves; the term is also applicable to a bubbly slaver dribbling from the mouth of one in a rage or in great excitement or to the clotted sweat of an animal driven to exhaustion or suffering from intense heat

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the rider from the chateau, and the horse in a foam, clattered away through the village— Dickens

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Of all these words foam commonly has the most pleasant associations, usually connoting in poetry whiteness, delicacy, and grace

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Idalian Aphrodite beautiful, fresh as the foam— Tennyson

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thefoam that looks so sunbright when the wind is kicking up the breakers— Warren

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Froth is applicable to any foam, but it carries a stronger implication of insubstantiality, worthlessness, or, when there is direct or indirect reference to persons or animals, of mad excitement than/bam carries

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your glass of beer is half froth

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froth forming at the mouth of a mad dog

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his speech had no logical substance, being mostly froth

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in all the froth and ferment between capital and labor— Furnas

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Spume is applicable where foam or froth might also be employed

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they dart forth polypus-antennae, to blister with their poison spume the wanderer— Shelley

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but the term is chiefly used to denote the foam arising on an agitated body of water

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all the billows green tossed up the silver spume against the clouds— Keats

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as when a sandbar breaks in clotted spume and spray— Kipling

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shore encumbered by rain-washed boulders and ruffed with sea spume— Han Suyin

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Scum distinctively applies to the bubbly film that rises on boiling liquids, especially those containing organic matter

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scum on boiling currant juice

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or to a similar film which forms on molten metals

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the scum or scoria of iron

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or on the surface of a body of stagnant water

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the ditch is covered with a green scum

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Such scums ordinarily constitute impurities that are removed (as from broth or molten metal) or that constitute a contamination impairing the usability (as of stagnant water); this notion of worthlessness or obnoxiousness is carried over into extended use especially as applied to a class or body of persons

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the social scum, the passively rotting mass of people who lie at the bottom of the social scale— Geismary

}

Lather and suds both apply to the foam produced by agitating water impregnated with soap or detergent.

Lather, however, usually suggests a less frothy condition than suds and a heavier aggregation of small soapy bubbles

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hard water does not produce a good lather for shaving

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Suds, on the other hand, often denotes water so covered with a soapy foam that it is usable for laundering clothes

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the laundress likes the soap because it gives her plenty of suds

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{

soak the cloth in hot suds

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Lather, rather than suds, may be preferred when the foam induced by intense sweating or emotional excitement is denoted

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a hard-ridden horse working up a lather

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he was in a lather of rage

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but suds is more usual when the reference is to something that suggests the appearance of suds in a laundry tub or washing machine

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another [medicine man] whips up a mixture of water and meal into frothy suds symbolic of clouds— Frazer

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Yeast basically applies to a froth or sediment composed of an aggregate of small fungal cells and found in saccharine liquids (as fruit juices and malt worts) in which it induces fermentation. The same substance is used as a leavening agent in bread; from this stems one line of its extended use in which it suggests a sign of activity, vitality, or agitation

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seething with the yeast of revolt— Dobie

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But because yeast often appears as a froth on liquids and is accompanied by fermentation, the term has another line of extended use in which it is applied to a similar froth, foam, or spume, especially one appearing on the surface of an agitated sea

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the ship . . . swallowed with yeast and froth— Shak.

}

{

they melt into thy yeast of waves— Byron

}