subside in WordNet English dictionary

1. wear off or die down
   "The pain subsided"
   subside  lessen 
   
2. sink down or precipitate
   "the mud subsides when the waters become calm"
   subside  settle 
   
3. descend into or as if into some soft substance or place
   "He sank into bed"; "She subsided into the chair"
   sink  subside 
   
4. sink to a lower level or form a depression
   "the valleys subside"
   subside