# foam

/ˈfoʊm/ (US) · /fˈəʊm/ (UK)

Source: https://englishreference.com/word/foam
Updated: 2026-06-20

## Senses

### 1. bubbles on a liquid

noun · CEFR B2

a mass of small bubbles that forms on the surface of a liquid.

For teachers: a collection of small bubbles formed on or in a liquid by agitation, fermentation, or chemical reaction.

- The waiter poured the beer carefully to keep the foam from spilling over.
- A thick layer of white foam gathered where the waves crashed against the jagged rocks of the shoreline.

### 2. soft material

noun · CEFR B2

a soft, light material used to make things like cushions, mattresses, or sponges.

For teachers: a lightweight, cellular solid material manufactured by trapping gas in a polymer, used for insulation or cushioning.

- The old sofa was uncomfortable because the foam inside had become too thin.
- The package was lined with protective foam to ensure the delicate electronic components were not damaged during transit.

### 3. the sea

noun · CEFR C2 · Literary

a poetic way to talk about the sea or the ocean.

For teachers: a metonymic or poetic reference to the sea, specifically the frothy surface of waves.

- The poet wrote about the white foam of the distant Atlantic.
- The ancient mariner watched the white foam trail behind the ship as they sailed toward the unknown horizon.

### 4. to produce bubbles

verb · CEFR B2

to produce or become covered in a mass of small bubbles.

For teachers: to produce, emit, or become converted into foam; often used of liquids being shaken or agitated.

- The soap began to foam as soon as she rubbed her hands together under the water.
- The chemical solution started to foam violently when the catalyst was introduced to the beaker.

### 5. to be very angry

verb · CEFR C1 · Informal

to be extremely angry about something.

For teachers: to exhibit signs of extreme rage or fury; typically used in the idiom 'foaming at the mouth'.

- My boss was practically foaming at the mouth when he saw the sales report.
- The protesters were foaming at the mouth with indignation after the controversial legislation was passed without a public hearing.

Usage: Usually appears in the phrase 'foaming at the mouth'.

## Examples

- The waves left white foam on the sand.
- The barista carefully poured the steamed milk to create a thick layer of foam on the latte.
- In the poet's description, the churning sea was a wild expanse of white foam and dark water, crashing relentlessly against the jagged cliffs.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.