a collection of minute bubbles formed on the surface of a liquid by agitation, fermentation, etc.: foam on a glass of beer.
the froth of perspiration, caused by great exertion, formed on the skin of a horse or other animal.
froth formed from saliva in the mouth, as in epilepsy and rabies.
a thick frothy substance, as shaving cream.
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.
a dispersion of gas bubbles in a solid, as foam glass, foam rubber, polyfoam, or foamed metal.
Literary. the sea.
to form or gather foam; emit foam; froth.
to cause to foam.
to cover with foam; apply foam to: to foam a runway before an emergency landing.
to insulate with foam.
to make (plastic, metal, etc.) into a foam.
Idioms about foam
foam at the mouth, to be extremely or uncontrollably angry.
- foam·a·ble, adjective
- foamer, noun
- foam·ing·ly, adverb
- foamless, adjective
- foamlike, adjective
- de·foam, verb (used with object)
- un·foamed, adjective
- un·foam·ing, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use foam in a sentence
Start with an insulated, inflatable pad, and consider layering it with a closed-cell foam pad for extra warmth.How to stay warm while sleeping in the frigid outdoors | Alisha McDarris | February 12, 2021 | Popular-Science
Two colleagues picked him up in a truck loaded with a foam mattress, a chair, two buckets, towels and a full water tank on the roof.
As a result, the shot’s trajectory will bend to the side or even down towards the floor if you want to rain little foam balls on your opponents from above.Nerf’s newest blaster shoots spinning balls for dramatic curves | Stan Horaczek | January 27, 2021 | Popular-Science
A slim-profile memory foam mattress less than 8 inches thick is going to work best for children and petite folks who weigh less than average.Best memory foam mattress: Sleep better on one of these picks | PopSci Commerce Team | January 25, 2021 | Popular-Science
These high-density foam organizers come in a wide variety of sizes, the smallest holding 30 bottles and the largest holding 63.Nail polish organizers to keep your collection in check | PopSci Commerce Team | January 20, 2021 | Popular-Science
The best example of that would be my first year when Kevin Hart hosted, we wrote a sketch called “foam Party.”How Aidy Bryant Stealthily Became Your Favorite ‘Saturday Night Live’ Star | Kevin Fallon | October 31, 2014 | THE DAILY BEAST
We need to take a razor and make a boundary in the shaving foam, people.Leo, the Beard Has to Go: When a Man’s Facial Hair Reaches Crisis Point | Tim Teeman | September 22, 2014 | THE DAILY BEAST
Near the Mason jars are foam heads, the kind a showgirl uses to style her wigs.Best Career Arc Ever: From Burlesque To Bartending | Anne Berry | September 13, 2014 | THE DAILY BEAST
I created the set, actually painted foam-core board to look like a door, and broke it out.The Wonderful Weirdness of Christine McConnell, Queen of Creepy Cookies | Tim Teeman | July 9, 2014 | THE DAILY BEAST
They chew this thing, a real thing, they do this until they foam at the mouth.
The train had long passed Hornberg, and far below the streams tumbled in white foam down the limestone rocks.Three More John Silence Stories | Algernon Blackwood
He had nearly bitten his swollen tongue in two falling over an unseen peat-cutting, and blood-flecked foam gathered on his lips.Uncanny Tales | Various
Harry was white with dust, blood was dripping from his left hand and his horse, white with foam, stood trembling.The Courier of the Ozarks | Byron A. Dunn
The storm which had for some time past been brewing, had fairly brewed itself up at last, and the wild sea was covered with foam.The Floating Light of the Goodwin Sands | R.M. Ballantyne
Stanley Hall and Jim Welton stood leaning over the taffrail, looking down into the black foam-streaked water.The Floating Light of the Goodwin Sands | R.M. Ballantyne
British Dictionary definitions for foam
a mass of small bubbles of gas formed on the surface of a liquid, such as the froth produced by agitating a solution of soap or detergent in water
frothy saliva sometimes formed in and expelled from the mouth, as in rabies
the frothy sweat of a horse or similar animal
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
a colloid consisting of a gas suspended in a liquid
a mixture of chemicals sprayed from a fire extinguisher onto a burning substance to create a stable layer of bubbles which smothers the flames
a poetic word for the sea
to produce or cause to produce foam; froth
(intr) to be very angry (esp in the phrase foam at the mouth)
- foamless, adjective
- foamlike, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for foam
Small, frothy bubbles formed in or on the surface of a liquid, as from fermentation or shaking.
A colloid in which particles of a gas are dispersed throughout a liquid. Compare aerosol emulsion.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.