frothing at the mouth
Literally 'foam at the corners of the mouth'; used to describe someone speaking with great excitement or anger, often in the phrase 口角泡を飛ばす.
彼は口角泡を飛ばして議論した。
He argued vehemently, frothing at the mouth.
Standard kanji spelling for this compound.
Mixed kanji-kana spelling; may be easier to read for learners.
Compound of 口角 (corners of the mouth) and 泡 (foam). The exact origin is uncertain, but it likely arose from the vivid image of someone speaking so passionately that foam gathers at the mouth.