Collins Chinese Dictionary Plus (3rd edition), 2011:
speechless [ˈspiːtʃlɪs]
adj
讲(講)不出话(話)的 jiǎng bù chū huà de
- to be speechless with rage/astonishment
气(氣)/惊(驚)讶(訝)得讲(講)不出话(話)来(來) qì/jīngyà de jiǎng bù chū huà lái