理屈詞窮

理屈词穷
qióng
  1. lit. having presented a flawed argument, one has nothing further to add (idiom)
  2. fig. unable to provide a convincing argument to support one's position
  3. to not have a leg to stand on

CEDICT

to be unable to put forth any convincing arguments to justify one's opinion; to not have a leg to stand on

Wiktionary

由於理虧反駁得無。《紅樓夢第一》:「理屈詞窮從此好好用功。」詞窮理屈」。

重編國語辭典

由於理虧反駁得無

維基詞典

Entry Composition