stagnate in WordNet English dictionary

1. be idle; exist in a changeless situation
   "The old man sat and stagnated on his porch"; "He slugged in bed all morning"
   idle  laze  slug  stagnate 
   
2. cease to flow; stand without moving
   "Stagnating waters"; "blood stagnates in the capillaries"
   stagnate 
   
3. stand still
   "Industry will stagnate if we do not stimulate our economy"
   stagnate 
   
4. cause to stagnate
   "There are marshes that stagnate the waters"
   stagnate