foam /fəum/ I. n. ［u］ 泡沫，泡沫材料：foam rubber 泡沫橡胶，海绵橡胶；form foam 起泡沫；the foam of the mouth 涎沫 ‖II.vi.起泡沫：foaming beer 起泡沫的啤酒 The stream foams over the rocks. 溪水泛着泡沫从岩石上流过。