ph.
1. 上床睡觉
When you turn in, you go to bed.
2. 把（犯罪嫌疑人）交给警方;告发;检举;自首
If you turn someone in, you take them to the police or tell the police where they are because they are suspected of committing a crime. If you turn yourself in, you go to the police because you have been involved in a crime.
3. 上交;提交;交付
When you turn in a completed piece of work, especially written work, you give it to the person who asked you to do it.
4. 交还;返还
If you turn something in, you return it to the place or person you borrowed it from.
1. prepare for sleep
e.g. I usually turn in at midnight
He goes to bed at the crack of dawn
Synonym: go to bedbedcrawl inkip downhit the hayhit the sacksack outgo to sleepretire
2. carry out (performances)
e.g. They turned in a splendid effort
They turned in top jobs for the second straight game
Synonym: put on
3. make an entrance by turning from a road
e.g. Turn in after you see the gate
4. to surrender someone or something to another
e.g. the guard delivered the criminal to the police
render up the prisoners
render the town to the enemy
fork over the money