stagnant  
adjective uk/ˈstæɡ.nənt/ us/ˈstæɡ.nənt/
  (NOT FLOWING)      
  (水或空气)不流动的,污浊的
(of water or air) not flowing or moving, and smelling unpleasant
  a stagnant pond 死水塘 
   (NOT BUSY)      
 停滞的,不发展的
not growing or developing
  a stagnant economy 停滞的经济