keep down in WordNet English dictionary

1. manage not to throw up
   keep down 
   
2. place a limit on the number of
   number  keep down 
   
3. put down by force or intimidation
   "The government quashes any attempt of an uprising"; "China keeps down her dissidents very efficiently"; "The rich landowners subjugated the peasants working the land"
   repress  quash  keep down  subdue  subjugate  reduce 
   

keep down in English Wiktionary