foam
This term evokes a sense of lightness and aeration, whether describing the natural froth of a crashing wave or the synthetic softness of a sponge. It carries a dual connotation: one of comfort and utility in industrial materials, and another of volatility or intensity when describing biological reactions.
When used as a verb in the phrase "foam at the mouth," the word shifts from a physical description of bubbles to a powerful metaphor for extreme rage or madness. This specific usage transforms the word from a neutral descriptor into a signal of loss of control.
Meanings
A lightweight, porous material made of plastic or rubber used for cushioning or insulation.
The mattress is made of high-density memory foam.
To produce a mass of small bubbles on the surface of a liquid.
The milk began to foam as the barista steamed it.
Examples
The waves left a trail of white foam on the sand.
The new running shoes have a thick layer of foam for support.
You should foam the milk before pouring it into the coffee.
The detergent will foam when you add it to the washing machine.
The angry bull began to foam at the mouth.
Phrasal Verbs
foam up
to form a mass of small bubbles quickly
The detergent will foam up as soon as you add water.
foam over
to produce so many bubbles that they spill over the edge of a container
Be careful not to let the milk foam over the top of the pitcher.