1 (also ˌfoam ˈrubber) a soft light rubber material that is used inside seats, cushions, etc （座位、垫子等里的）泡沫橡胶: a foam mattress 泡沫橡胶床垫

2 a mass of small air bubbles that form on the surface of a liquid 泡沫: white foam on the tops of the waves 浪花的泡沫

3 an artificial substance that is between a solid and a liquid and is made from very small bubbles 像泡沫一样的人造物质: shaving foam 剃须膏