破口

tear or rupture / to have a tear (e.g. in one's clothes) / without restraint (e.g. of swearing)

broken / damaged / worn out / lousy / rotten / to break, split or cleave / to get rid of / to destroy / to break with / to defeat / to capture (a city etc) / to expose the truth of

mouth / classifier for things with mouths (people, domestic animals, cannons, wells etc) / classifier for bites or mouthfuls

breach / gap / breakthrough point

to abuse roundly

incessant complaining