zhēng​téng​zuò​yòng

transpiration

  1. transpiration
    the process of water movement through a plant and its evaporation from aerial parts such as leaves, stems, and flowers
  2. function
    the natural purpose or activity of something, such as a biological or chemical process; often used as a suffix to mean "-ation" or "-ing" as in 消化 xiāo​huà plus this word for "digestion"