螳 tang2 螳
臂 bi4 臂
当 dang1 當
车 che1 車
  1. lit. a mantis trying to stop a chariot (idiom)
  2. fig. to overrate oneself and attempt sth impossible
  3. also written 螳臂擋車|螳臂挡车[tang2 bi4 dang3 che1]

Info