We sealed the attic gaps with spray foam, a chemical product made by mixing isocyanate and polyol resin that reacts and expands up to 30–60 times its liquid volume after being sprayed in place.

The fans shook their foam hands in unison during the final minute.

At the championship game, fans waved foam fingers and cheered for their team.

He squeezed a dollop of shave foam onto the palm of his hand before starting to shave.

A foam finger bobbed above the crowd as the team scored the winning goal.

The magician reached into the air and produced a cloud of vanishing foam that dissolved before anyone could touch it.

Many manufacturers add foaming agents to their products to improve texture and reduce density.

The beverage manufacturer added an anti-foaming agent to the cider to prevent excessive effervescence during fermentation.

To control foam in the fermentation process, we add anti-foaming agents at regular intervals.