expression, godan verb (-su)
argue heatedly; debate with foam at the mouth
Idiomatic expression describing a very passionate, often loud argument where the speaker is so worked up that spittle flies. Conveys intensity and emotional involvement.
彼らは政治の話になると、いつも口角泡を飛ばして議論する。
Whenever politics comes up, they always argue heatedly, foam flying from their mouths.
The audience was overwhelmed by the fervent speech, delivered with such passion that spittle flew.