Giving off bubbles and developing a head of foam; as, a foaming glass of beer.

In a boiler, the carry-over of slugs of water into the piping due to dirty water or overloading of the boiler. Compare PRIMING.

The continuous formation of bubbles which have sufficiently high surface tension to remain as bubbles beyond the disengaging surface.

During mixing or filling, the undesired result of excessive aeration of a mixture.

A potential problem, occuring during rapid coolant filling operations as at the OEM factory. Foaming can lead to underfill situations and air entrainment. All good coolants will contain anti-foam agents as part of their add pack to eliminate foaming tencencies

Formation of foam in an oil-refrigerant mixture due to rapid evaporation of liquid refrigerant dissolved in the oil.

producing or covered with lathery sweat or saliva from exhaustion or disease; "the rabid animal's frothing mouth"