1. a mass of small bubbles formed on or in liquid
2. a light, spongy material made by trapping gas bubbles in a solid or liquid

1. to produce foam or froth
2. to be very angry
Usage: informal

Examples

• The waves crashed against the rocks, creating white foam.
• She added soap to the water until it produced thick foam.
• The mattress was made of memory foam for comfort.
• The beer began to foam when he opened the bottle.
• The angry customer was foaming at the mouth.
• Foam insulation helps keep the house warm.
• The cappuccino had a layer of milk foam on top.