- a chemically produced substance that smothers the flames on a burning liquid by forming a layer of minute, stable, heat-resistant bubbles on the liquid's surface.
- the layer of bubbles so formed.
verb (used without object)
verb (used with object)
Origin of foam
Synonyms for foam
- any of a number of light cellular solids made by creating bubbles of gas in the liquid material and solidifying it: used as insulators and in packaging
- (as modifier)foam rubber; foam plastic
Word Origin for foam
Old English fam "foam, saliva froth," from West Germanic *faimo- (cf. Old High German veim, German Feim), from PIE *(s)poi-mo-, a root with connotations of "foam, froth" (cf. Sanskrit phenah; Latin pumex "pumice," spuma "foam;" Old Church Slavonic pena "foam;" Lithuanian spaine "a streak of foam"). The rubber or plastic variety so called from 1937.
Old English famgian "to foam," from the source of foam (n.). Related: Foamed; foaming.
foam at the mouth
Be extremely angry, as in She was foaming at the mouth over the judge's ruling. This hyperbolic term uses the verb foam in the sense of “froth at the mouth,” a usage generally applied to animals such as horses and dating from about a.d. 950. [1400s]