1. foam at the mouth - Verb
2. foam at the mouth - Phrase
be in a state of uncontrolled anger
Source: WordNetIn a jungle town Where the sun beats down To the rage of man and beast, The English garb Of the English sahib Merely gets a bit more creased. In Bangkok At twelve'o'clock They foam at the mouth and run, But mad dogs and Englishmen Go out in the midday sun. Noël Coward