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foam

n. · v.
US //ˈfoʊm// UK //fˈəʊm// foam
  1. 1 bubbles on a liquid (n.)
    B2 Upper Intermediate

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

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

    Example

    The waiter poured the beer carefully to keep the foam from spilling over.

    Example

    A thick layer of white foam gathered where the waves crashed against the jagged rocks of the shoreline.
  2. 2 soft material (n.)
    B2 Upper Intermediate

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

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

    Example

    The old sofa was uncomfortable because the foam inside had become too thin.

    Example

    The package was lined with protective foam to ensure the delicate electronic components were not damaged during transit.
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  1. 3 the sea (n.)
    C2 Proficiency Literary

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

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

    Example

    The poet wrote about the white foam of the distant Atlantic.

    Example

    The ancient mariner watched the white foam trail behind the ship as they sailed toward the unknown horizon.
  2. 4 to produce bubbles (v.)
    B2 Upper Intermediate

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

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

    Example

    The soap began to foam as soon as she rubbed her hands together under the water.

    Example

    The chemical solution started to foam violently when the catalyst was introduced to the beaker.
  3. 5 to be very angry (v.)
    C1 Advanced Informal

    to be extremely angry about something.

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

    Example

    My boss was practically foaming at the mouth when he saw the sales report.

    Example

    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'.
Origin

From Middle English fom, foom, from Old English fām, from Proto-West Germanic faim, from Proto-Germanic faimaz, from Proto-Indo-European (s)poHy-m-os, from (s)poH(y)- (“foam”). Cognate with German Feim (“foam”), Latin spūma (“foam”), Latin pūmex (“pumice”), Sanskrit फेन (phéna, “foam”), possibly Northern Kurdish fê (“epilepsy”).

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