Foam

1. n. The white substance, consisting of an aggregation of bubbles, which is formed on the surface of liquids, or in the mouth of an animal, by violent agitation or fermentation; froth; spume; scum; as, the foam of the sea.
2. n. To gather foam; to froth; as, the billows foam.
3. n. To form foam, or become filled with foam; — said of a steam boiler when the water is unduly agitated and frothy, as because of chemical action.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.