ㄌㄧˇㄑㄩˊㄑㄩㄥˊqióng

  1. 由於理虧反駁無話可說紅樓夢·第一》:理屈詞窮從此好好用功。」詞窮理屈」。張口結舌理直氣壯振振義正詞嚴

faulty argument and poor rhetoric (idiom)​; unable to put forward any convincing arguments, without a leg to stand on