ˋㄓㄥˋzhèngˊㄧㄢˊyán

  1. 理由正當措詞嚴厲這番義正辭嚴指責無言以對。」義正詞嚴」。理直氣壯理屈詞窮強詞奪理張口結舌油腔滑調

to speak forcibly out of a sense of righteousness (idiom)​