丈二和尚，摸不着头脑
zhàng'èr​hé​shang​mō​bu​zháo​tóu​nǎo

at a total loss

  1. 丈二和尚 zhàng'èr​hé​shàng
    to be at a loss
    Completely puzzled or unable to understand the cause or development of a situation; first part of a two-part allegorical saying (xiehouyu) with the punchline 摸不着头脑 mō​bu​zháo​tóu​nǎo
  2. ， mō
    non-Chinese
  3. 摸不着头脑 摸不著頭腦 mō​bu​zháo​tóu​nǎo
    to be at a loss
    To be unable to make any sense of a matter or understand what is going on; to be completely baffled