foam

1 of 3

noun (1)

ˈfōm 

1

: a light frothy mass of fine bubbles formed in or on the surface of a liquid or from a liquid: such as

a

: a frothy mass formed in salivating or sweating

b

: a stabilized froth produced chemically or mechanically and used especially in fighting oil fires

c

: a material in a lightweight cellular form resulting from introduction of gas bubbles during manufacture

2

: sea

3

: something resembling foam

foamless

ˈfōm-ləs 

adjective

foam

2 of 3

verb

foamed; foaming; foams

intransitive verb

1

a

: to produce or form foam

b

: to froth at the mouth especially in anger

broadly : to be angry

2

: to gush out in foam

3

: to become covered with or as if with foam

… streets … foaming with life …

—Thomas Wolfe

transitive verb

1

: to cause to foam

specifically : to cause air bubbles to form in

2

: to convert (something, such as a plastic) into a foam

foamable

ˈfō-mə-bəl 

adjective

foamer

ˈfō-mər 

noun

foamer

3 of 3

noun (2)

foam·​er ˈfōmə(r) 

plural -s

: one that foams

foamers crashing on the shore

Synonyms of foam

Noun (1)

• surf
• suds
• froth
• spray
• head

Verb

• steam
• storm
• rage
• boil
• burn
• shake

Examples of foam in a Sentence

Noun (1)

As I poured the beer, foam bubbled up in the glass.

The fire extinguisher is filled with foam.

a can of shaving foam

Verb

The soda foamed in the glass.

The mixture will bubble and foam when you add the yeast.

Recent Examples on the Web

Noun

The machine-washable sneakers have a soft, suede-like finish and bouncy foam insoles for extra cushioning. — Jeaneen Russell, PEOPLE, 30 Sep. 2026

Its foam comfort layer can change as the sleeper’s preferences do, while the hybrid structure beneath it is designed to provide support. — Malana Vantyler, Miami Herald, 30 Sep. 2026

Verb

Cook, stirring occasionally and keeping a close watch, until mixture begins to foam up and boil, about 5 minutes. — Carla Lalli Music, Bon Appetit Magazine, 25 Sep. 2026

For the best results, Dyson recommends using toothpaste without foaming agents. — Maryna Holovnova, New Atlas, 16 Sep. 2026

Word History

Etymology

Noun (1)

Middle English fome, from Old English fām; akin to Old High German feim foam, Latin spuma foam, pumex pumice

First Known Use

Noun (1)

before the 12th century, in the meaning defined at sense 1

Verb

before the 12th century, in the meaning defined at intransitive sense 1a

Phrases Containing foam

• cell foam
• cellular foam
• closed-cell foam
• foam at the mouth
• foam cell
• foam rubber
• memory foam
• open-cell foam
• plastic foam
• shaving foam

Rhymes for foam

• brome
• chrome
• comb
• combe
• crome
• dome
• gnome
• holm
• loam
• roam
• tome
• acrosome

Kids Definition

foam

1 of 2 noun

ˈfōm 

1

: a light mass of fine bubbles formed in or on a liquid

2

: a mass of fine bubbles formed (as by a horse) in producing saliva or sweating

3

: a long-lasting mass of bubbles produced chemically and used especially in fighting oil fires

4

: a material (as rubber) in a lightweight cellular form resulting from the presence of gas bubbles during manufacture

foamily

ˈfō-mə-lē

adverb

foaminess

ˈfō-mē-nəs

noun

foamy

-mē

adjective

foam

2 of 2 verb

1

: to produce or form foam : froth

2

: to be angry

Medical Definition

foam

noun

ˈfōm 

: a light frothy mass of fine bubbles formed in or on the surface of a liquid

spermicidal foam

foam verb