顿口无言

頓口無言
dùnkǒuwúyán

to have nothing to say in response

Wiktionary

Entry Composition

1 顿 dùn
  1. to stop
  2. to pause
  3. to arrange
  4. to lay out
  5. to kowtow
  6. to stamp (one's foot)
  7. at once
  8. classifier for meals, beatings, scoldings etc: time, bout, spell, meal
2 口 kǒu
  1. mouth
  2. classifier for things with mouths (people, domestic animals, cannons, wells etc)
  3. classifier for bites or mouthfuls
3 无言 wúyán
  1. to remain silent
  2. to have nothing to say