Froth is a mass of small bubbles on the surface of a liquid.
foam
the froth of bubbles on the top of a glass of beer.
一杯啤酒顶上的泡沫。
froths , frothing , frothed
If a liquid froths, small bubbles appear on its surface.
The sea froths over my feet.
海水在我脚上泛起泡沫。