turn in in WordNet English dictionary

1. prepare for sleep
   "I usually turn in at midnight"; "He goes to bed at the crack of dawn"
   go to bed  turn in  bed  crawl in  kip down  hit the hay  hit the sack  sack out  go to sleep  retire 
   
2. to surrender someone or something to another
   "the guard delivered the criminal to the police"; "render up the prisoners"; "render the town to the enemy"; "fork over the money"
   hand over  fork over  fork out  fork up  turn in  deliver  render 
   
3. carry out (performances)
   "They turned in a splendid effort"; "They turned in top jobs for the second straight game"
   put on  turn in 
   
4. make an entrance by turning from a road
   "Turn in after you see the gate"
   turn in 
   

turn in in English Wiktionary