泛滥成灾
fàn​làn​chéng​zāi

to flood disastrously

fàn​làn​chéng​zāi to flood disastrously
  1. 泛滥 泛濫 fàn​làn verb
    to flood
    to overflow the banks; to inundate a wide area
  2. 成灾 成災 chéng​zāi
    to turn into a disaster
    to result in a calamity; to cause disaster (often used as a resultative complement)

fàn​làn​chéng​zāi to run wild
  1. 泛滥 泛濫 fàn​làn
    to go rampant
    to spread unchecked; to proliferate or become widespread, usually describing something harmful or undesirable
  2. 成灾 成災 chéng​zāi
    to reach plague proportions
    to become an infestation or plague; to cause damage through overabundance or swarming (e.g. of pests)