turn back in WordNet English dictionary

1. hold back, as of a danger or an enemy; check the expansion or influence of
   "Arrest the downward trend"; "Check the growth of communism in South East Asia"; "Contain the rebel movement"; "Turn back the tide of communism"
   check  turn back  arrest  stop  contain  hold back 
   
2. retrace one's course
   "The hikers got into a storm and had to turn back"
   backtrack  turn back  double back 
   
3. force to go away; used both with concrete and metaphoric meanings
   "Drive away potential burglars"; "drive away bad thoughts"; "dispel doubts"; "The supermarket had to turn back many disappointed customers"
   chase away  drive out  turn back  drive away  dispel  drive off  run off 
   
4. turn inside out or upside down
   turn back  invert  reverse 
   
5. go back to a previous state
   "We reverted to the old rules"
   revert  return  retrovert  regress  turn back 
   

turn back in English Wiktionary